Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Molecules ; 28(21)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37959739

RESUMO

Radix Paeoniae Alba (RPA) has been used extensively in Chinese traditional medicine to treat gastrointestinal disorders, immune-modulating diseases, cancers, and numerous other conditions. A few of its active components include paeoniflorin, albiflorin, lactiflorin, and catechin. However, their therapeutic effectiveness is compromised by poor pharmacokinetic profiles, low oral bioavailability, short half-lives, and poor aqueous solubility. In this study, hydroxyethyl cellulose-grafted-2-acrylamido-2-methylpropane sulfonic acid (HEC-g-AMPS) hydrogels were successfully prepared for the controlled release of Radix Paeonia Alba-solid dispersion (RPA-SD). A total of 43 compounds were identified in RPA-SD using UHPLC-Q-TOF-MS analysis. The hydrogel network formation was confirmed by FTIR, TGA, DSC, XRD, and SEM. Hydrogels' swelling and drug release were slightly higher at pH 1.2 (43.31% swelling, 81.70% drug release) than at pH 7.4 (27.73% swelling, 72.46% drug release) after 48 h. The gel fraction, drug release time and mechanical strength of the hydrogels increased with increased polymer and monomer concentration. Furthermore, the hydrogels were porous (84.15% porosity) and biodegradable (8.9% weight loss per week). Moreover, the synthesized hydrogels exhibited excellent antimicrobial and antioxidative properties.


Assuntos
Medicamentos de Ervas Chinesas , Paeonia , Medicamentos de Ervas Chinesas/química , Paeonia/química , Preparações de Ação Retardada , Hidrogéis , Celulose
2.
Environ Geochem Health ; 45(11): 8015-8030, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37523030

RESUMO

Dietary intake of toxic elements (TEs) and essential trace elements (ETEs) can significantly impact human health. This study collected 302 samples, including 78 food, 104 drinking water, 73 cultivated topsoil, and 47 sedimentary rock from a typical area of Tethys-Himalaya tectonic domain. These samples were used to calculate the average daily dose of oral intake (ADDoral) and assess the health risks of five TEs and five ETEs. The results indicate that grain and meat are the primary dietary sources of TEs and ETEs for local residents. The intake of manganese (Mn) and copper (Cu) is mainly from local highland barley (66.90% and 60.32%, respectively), iron (Fe) is primarily from local grains (75.51%), and zinc (Zn) is mainly from local yak meat (60.03%). The ADDoral of arsenic (As), Mn, Fe and Zn were found to be higher than the maximum oral reference dose in all townships of study area, indicating non-carcinogenic health risks for local residents. Additionally, lead (Pb) and nickel (Ni) in 36.36% townships, and Cu in 81.82% townships were above the maximum oral reference dose, while As posed a carcinogenic risk throughout the study area. The concentrations of As, mercury (Hg), Pb, Mn, Cu Fe and selenium (Se) in grains were significantly correlated with those in soils. Moreover, the average concentrations of As in Proterozoic, Triassic, Jurassic and Cretaceous was 43.09, 12.41, 15.86 and 6.22 times higher than those in the South Tibet shell, respectively. The high concentrations of TEs and ETEs in the stratum can lead to their enrichment in soils, which, in turn, can result in excessive intake by local residents through the food chain and biogeochemical cycles . To avoid the occurrence of some diseases caused by dietary intake, it is necessary to consume a variety of exotic foods, such as high-selenium foods, foreign rice and flour in order to improve the dietary structure.


Assuntos
Arsênio , Mercúrio , Metais Pesados , Selênio , Oligoelementos , Humanos , Oligoelementos/análise , Selênio/análise , Tibet , Chumbo , Arsênio/análise , China , Mercúrio/análise , Manganês , Solo/química , Medição de Risco , Metais Pesados/análise
3.
J Appl Microbiol ; 132(1): 189-198, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34309978

RESUMO

The experiment aimed to compare the effects of citric acid residue (CAR) to that of three commonly used short-chain fatty acids on the fermentation quality, aerobic stability and structural carbohydrate degradation of lucerne ensiled with lactic acid bacteria (LAB) inoculants. Fresh lucerne was ensiled with distilled water (control), LAB inoculant (L), CAR + LAB inoculant (CL), formic acid + LAB inoculant (FL), acetic acid + LAB inoculant (AL) and propanoic acid + LAB inoculant (PL) for 50 days. Chemical composition and microbial populations were determined after ensiling. The residual silages ensiled for 50 days were evaluated for aerobic stability. Compared with control, CL, FL, AL and PL treatments significantly (p < 0.05) decreased pH, ammonia nitrogen (NH3 -N) and butyric acid contents and increased lactic acid, acetic acid and propionic acid contents. Among them, CL silages had the lowest pH, dry matter and water-soluble carbohydrate (WSC) content, whereas the population of LAB and the lactic acid contents were highest. Besides, CL outperformed in enhancing fibre degradation, CL silages significantly decreased (p < 0.05) neutral detergent fibre, acid detergent fibre, hemicellulose and cellulose contents compared with control and had the highest Flieg's point. All treated-silages improved the aerobic stability compared with control, of which L improved 32 h, whereas CL, FL, AL and PL improved 46, 20, 46, >64 h, respectively. Applying a combination of CAR and LAB inoculant improved the fermentation quality and structural carbohydrate degradation of lucerne silage and had a similar effect on aerobic stability compared with other three short-chain fatty acids. The CAR had a comparable effect on enhancing the fermentation quality compared with three short-chain fatty acids. Thus, the combination of CAR and LAB inoculant might be used as an ideal additive for lucerne silage making with low WSC and high moisture content.


Assuntos
Inoculantes Agrícolas , Medicago sativa , Ácido Acético , Aerobiose , Ácido Cítrico , Fermentação , Ácido Láctico , Lactobacillus , Silagem/análise
4.
Molecules ; 27(20)2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36296486

RESUMO

Alzheimer's disease is the most common neurodegenerative disease, characterized by memory loss and cognitive dysfunction. Raspberry fruits contain polyphenols which have antioxidant and anti-inflammatory properties. In this study, we used molecular imprinting technology to efficiently isolate phenolic components from the raspberry ethyl acetate extracts. Six phenolic components (ellagic acid, tiliroside, kaempferol-3-o-rutoside, gallic acid, ferulic acid and vanillic acid) were identified by UPLC-Q-TOF-MS analysis. Molecular docking was used to predict the anti-inflammatory effects and anti-Alzheimer's potential of these isolated compounds, which showed a good binding ability to diseases and related proteins. However, the binding energy and docking fraction of ellagic acid, tiliroside, and kaempferol-3-o-rutoside were better than those of gallic acid, ferulic acid and vanillic acid. Additionally, by studying the effects of these six phenolic components on the LPS-induced secretion of inflammatory mediators in murine microglial (BV2) cells, it was further demonstrated that they were all capable of inhibiting the secretion of NO, IL-6, TNF-α, and IL-1ß to a certain extent. However, ellagic acid, tiliroside, and kaempferol-3-o-rutoside have better inhibitory effects compared to others. The results obtained suggest that the phenolic components extracted from ethyl acetate extracts of raspberry by molecularly imprinted polymers have the potential to inhibit the progression of Alzheimer's disease.


Assuntos
Impressão Molecular , Doenças Neurodegenerativas , Rubus , Camundongos , Animais , Rubus/química , Antioxidantes/química , Quempferóis/farmacologia , Ácido Elágico/farmacologia , Ácido Elágico/análise , Simulação de Acoplamento Molecular , Fator de Necrose Tumoral alfa , Ácido Vanílico/farmacologia , Polímeros Molecularmente Impressos , Interleucina-6 , Lipopolissacarídeos , Extratos Vegetais/química , Anti-Inflamatórios/farmacologia , Ácido Gálico/farmacologia , Rutina , Mediadores da Inflamação
5.
Molecules ; 27(23)2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36500491

RESUMO

Traditional wound dressings often cannot treat wounds caused by bacterial infections or other wound types that are insensitive to these wound treatments. Therefore, a biodegradable, bioactive hydrogel wound dressing could be an effective alternative option. The purpose of this study was to develop a hydrogel membrane comprised of sodium alginate, polyvinyl alcohol, acrylic acid, and gallic acid for treating skin wounds. The newly developed membranes were analyzed using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), sol-gel fraction, porosity, mechanical strength, swelling, drug release and data modelling, polymeric network parameters, biodegradation, and antioxidation (DPPH and ABTS) and antimicrobial activity against Gram-positive and negative bacteria. The results revealed that hydrogel membranes were crosslinked successfully and had excellent thermal stability, high drug loading, greater mechanical strength, and exhibited excellent biodegradation. Additionally, the swelling ability and the porosity of the surface facilitated a controlled release of the encapsulated drug (gallic acid), with 70.34% release observed at pH 1.2, 70.10% at pH 5.5 (normal skin pH), and 86.24% at pH 7.4 (wounds pH) in 48 h. The gallic acid-loaded hydrogel membranes showed a greater area of inhibition against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli bacteria as well as demonstrated excellent antioxidant properties. Based on Franz cell analyses, the permeation flux of the drug from optimized formulations through mice skin was 92 (pH 5.5) and 110 (pH 7.4) µg/cm2·h-1. Moreover, hydrogel membranes retained significant amounts of drug in the skin for 24 h, such as 2371 (pH 5.5) and 3300 µg/cm2 (pH 7.4). Acute dermal irritation tests in rats showed that hydrogel membranes were nonirritating. Hydrogel membranes containing gallic acid could be an effective option for improving wound healing and could result in faster wound healing.


Assuntos
Hidrogéis , Álcool de Polivinil , Camundongos , Ratos , Animais , Álcool de Polivinil/química , Hidrogéis/química , Alginatos/farmacologia , Ácido Gálico/farmacologia , Escherichia coli , Antibacterianos/farmacologia , Antibacterianos/química
6.
Environ Geochem Health ; 41(3): 1507-1520, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30599055

RESUMO

Life expectancy is influenced by both innate human self-factors and external environmental factors. Due to the individual difference of self-factors, the external environment impacts on life expectancy are especially important under the geoscience perspective. However, few studies discussed impacts of various socioeconomic and environmental factors comprehensively, and quantitative analysis of multi-factors is lacking. We chose 13 potential factors of socio-economy, ecological environment, geological environment and geographical environment to quantitatively analyze their impacts and their interactive influences on Tibet's life expectancy in 2010 by using geographical detector (Geodetector) algorithm, and figure out their suitable ranges or types. Our results indicated that the high life expectancy at birth in Tibet are distributed like a strip; the main control factor of life expectancy in Tibet is socioeconomy, followed by geological environment; furthermore, the highest range of socioeconomic factors and the igneous rock exposed areas correspond to the maximum value of life expectancy at birth; factors of ecological environment have a certain impact on the life expectancy of Tibetan residents, while factors of geographical environment have few effects on the life expectancy. Lower radiation, moderate temperature and rainfall may have favorable effects on the increase in the life expectancy. The life expectancy of Tibet is mainly affected by socioeconomy, geological and ecological environment; interactions between these factors can increase the impact on the life expectancy of Tibet. Consequently, this study can better understand the impact factors of the life expectancy in Tibet and could provide a reference basis for local government's policy making of relocation and population management.


Assuntos
Expectativa de Vida , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Altitude , Meio Ambiente , Feminino , Produto Interno Bruto , Humanos , Masculino , Plantas , Fatores Socioeconômicos , Temperatura , Tibet
7.
J Environ Manage ; 210: 280-289, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29407188

RESUMO

Anthropogenic activities have induced profound changes across the globe. Human appropriation of net primary production (HANPP) is a useful indicator for quantifying anthropogenic influences on natural ecosystems. We applied a detailed HANPP framework to the Tibet Autonomous Region of China for the period 1989-2015 and performed clustering analysis to explore county-level dynamics of HANPP components. The results indicated a continuous increase in HANPP per unit area from 10.3 g C/m2/yr in 1989 to 18.5 g C/m2/yr in 2008, with some fluctuation and a decline to 16.8 C/m2/yr in 2015. As a percentage of potential net primary production (NPPpot), HANPP increased from 6.9% to 13.5%. This rise was mainly driven by the commercialization of animal husbandry and by ecological conservation policies. Animal stocks dominated HANPP in Tibet in 1989, and by 2015 beef or crop production had become predominant in 30 of 73 counties. However, HANPP did not change uniformly across all locations. Changes were mainly concentrated in the south-central river valley area because of the growth in beef and crop production there. While in almost half of the 73 counties located in the northwestern regions, HANPP was dominated by sheep stocks and changed only slightly over the study period. These findings indicate that a comprehensive spatiotemporal analysis of HANPP components in Tibet provides deeper insights into changes in production and livelihood strategies of local residents, aligned with ecological conservation policies and economic development. Moreover, it unravels the complex impacts of human activities on alpine ecosystems, and indicates the need to optimize local ecosystem management and conservation policies.


Assuntos
Ecossistema , Atividades Humanas , Animais , China , Monitoramento Ambiental , Humanos , Rios , Ovinos , Tibet
8.
J Environ Manage ; 193: 70-78, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28189931

RESUMO

Developing sustainable use patterns for alpine grassland in Tibet is the primary challenge related to conserving these vulnerable ecosystems of the 'world's third pole' and guaranteeing the well-being of local inhabitants. This challenge requires researchers to think beyond the methods of most current studies that are limited to a single aspect of conservation or productivity, and focus on balancing various needs. An analysis of trade-offs involving ecosystem services provides a framework that can be used to quantify the type of balancing needed. In this study, we measured variations in four types of ecosystem services under five types of grassland management including grazing exclusion, sowing, combined plowing and grazing exclusion, combined plowing and sowing, and natural grassland, from 2013 to 2015. In addition, we accessed the existence and changing patterns of ecosystem service trade-offs using Spearman coefficients and a trade-off index. The results revealed the existence of trade-offs among provisioning and regulating services. Plowing and sowing could convert the trade-off relationships into synergies immediately. Grazing exclusion reduced the level of trade-offs gradually over time. Thus, the combined plowing and sowing treatment promoted the total supply of multiple ecosystem services when compared with natural grassland. We argue that the variations in dry matter allocation to above- and belowground serve as one cause of the variation in trade-off relationships. Another cause for variation in trade-offs is the varied species competition between selection effects and niche complementarity. Our study provides empirical evidence that the effects of trade-offs among ecosystem services could be reduced and even converted into synergies by optimizing management techniques.


Assuntos
Ecossistema , Pradaria , China , Tibet
9.
Environ Monit Assess ; 187(8): 491, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26148691

RESUMO

It is the most serious challenge to promote degraded grassland recovery currently facing the developing Tibetan Autonomous Region. We conducted field surveys of 75 grazing sites between 2009 and 2012 across the Northern Tibetan Plateau and described the spatial and climatic patterns of the occurrence of poisonous plants. Our results showed lower ratios of species richness (SprRatio), coverage (CovRatio), and biomass (BioRatio) of non-poisonous vs. poisonous plants in the semi-arid alpine steppe zone, where the growing season precipitation (GSP) is between 250 and 350 mm; however, this result is in contrast to the relatively wetter meadow (GSP >350 mm) and much drier desert-steppe (GSP <250 mm) communities. Results from generalized additive models (GAMs) further confirmed that precipitation is primarily responsible for the initially decreasing and then increasing tendency of compositional ratios of non-poisonous to poisonous species. The wide confidence bands at GSP <250 mm indicated that precipitation is not an effective indicator for predicting compositional changes in desert-steppe communities. When mean annual livestock grazing pressure was incorporated into the optimal GAMs, the model performance improved: the Akaike information criterion (AIC) decreased by 1.20 for SprRatio and 3.09 for BioRatio, and the deviance explained (R (2)) increased by 6.0% for SprRatio and 3.6% for BioRatio. Therefore, more detailed information on grazing disturbance (timing, frequency, and density) should be collected to disentangle the relative contribution of climate change and grazing activities to changes in community assembly and ecological functions of alpine grasslands on the Northern Tibetan Plateau.


Assuntos
Mudança Climática , Ecossistema , Monitoramento Ambiental/métodos , Plantas Tóxicas/crescimento & desenvolvimento , Poaceae/crescimento & desenvolvimento , Altitude , Biodiversidade , Biomassa , Clima Desértico , Modelos Teóricos , Estações do Ano , Especificidade da Espécie , Tibet
10.
ScientificWorldJournal ; 2014: 265142, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24790558

RESUMO

Alpine meadows are one major type of pastureland on the Tibetan Plateau. However, few studies have evaluated the response of soil respiration (R(s)) to grazing along an elevation gradient in an alpine meadow on the Tibetan Plateau. Here three fenced enclosures were established in an alpine meadow at three elevations (i.e., 4313 m, 4513 m, and 4693 m) in July 2008. We measured R s inside and outside the three fenced enclosures in July-September, 2010-2011. Topsoil (0-20 cm) samples were gathered in July, August, and September, 2011. There were no significant differences for R s , dissolved organic C (DOC), and belowground root biomass (BGB) between the grazed and ungrazed soils. Soil respiration was positively correlated with soil organic C (SOC), microbial biomass (MBC), DOC, and BGB. In addition, both R s and BGB increased with total N(TN), the ratio of SOC to TN, ammonium NH4 ⁺-H4⁺-N), and the ratio of NH4⁺-N to nitrate N. Our findings suggested that the negligible response of R s to grazing could be directly attributed to that of respiration substrate and that soil N may indirectly affect R(s) by its effect on BGB.


Assuntos
Ecossistema , Solo/química , Tibet
11.
ScientificWorldJournal ; 2014: 152576, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24977179

RESUMO

Although alpine meadows of Tibet are expected to be strongly affected by climatic warming, it remains unclear how soil organic C (SOC), total N (TN), ammonium N (NH4 (+)-N) , nitrate N (NO3 (+)-N), and dissolved organic C (DOC) and N (DON) respond to warming. This study aims to investigate the responses of these C and N pools to short-term experimental warming in an alpine meadow of Tibet. A warming experiment using open top chambers was conducted in an alpine meadow at three elevations (i.e., a low (4313 m), mid-(4513 m), and high (4693 m) elevation) in May 2010. Topsoil (0-20 cm depth) samples were collected in July-September 2011. Experimental warming increased soil temperature by ~1-1.4°C but decreased soil moisture by ~0.04 m(3) m(-3). Experimental warming had little effects on SOC, TN, DOC, and DON, which may be related to lower warming magnitude, the short period of warming treatment, and experimental warming-induced soil drying by decreasing soil microbial activity. Experimental warming decreased significantly inorganic N at the two lower elevations,but had negligible effect at the high elevation. Our findings suggested that the effects of short-term experimental warming on SOC, TN and dissolved organic matter were insignificant, only affecting inorganic forms.


Assuntos
Altitude , Carbono/análise , Aquecimento Global , Compostos Inorgânicos/análise , Compostos de Nitrogênio/análise , Compostos Orgânicos/análise , Solo/química , Monitoramento Ambiental , Tibet
12.
Asian-Australas J Anim Sci ; 27(3): 349-56, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25049961

RESUMO

The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR) silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM) was ensiled with four different treatments: no additive (control), molasses (M), propionic acid (P), and molasses+propionic acid (PM), in laboratory silos (250 mL) and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN), and high lactic acid (LA) content and V-scores. M silage showed the highest (p<0.05) LA content and higher dry matter (DM) recovery than the control and P silages. P silage had lower (p<0.05) LA content than the control silage. During aerobic exposure, lactic acid contents decreased gradually in the control and M silages, while that of P and PM silages increased, and the peak values were observed after 9 d. M silage had similar yeast counts with the control silage (>10(5) cfu/g FM), however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (<10(5) cfu/g FM) (p<0.05) and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage.

13.
Int J Biol Macromol ; 273(Pt 1): 132825, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38852724

RESUMO

Glycyrrhiza glabra Linn (liquorice) has been widely used for therapeutic purposes to treat digestive disorders, immunomodulatory disorders, inflammatory disorders, diabetes, viral infections, and cancer. Liquorice contains a wide variety of bioactive compounds, including glycyrrhizin, flavonoids, and terpenoids. Several factors compromise their therapeutic efficacy, such as poor pharmacokinetic profiles and physicochemical properties. Therefore, to improve its overall effectiveness, liquorice solid dispersion (LSD) was incorporated into biopolymer-based guar gum-grafted-2-acrylamido-2-methylpropane sulfonic acid (Guar gum-g-AMPS) hydrogels designed for controlled delivery via the oral route and characterized. The qualitative analysis of LSD revealed 51 compounds. Hydrogel structural properties were assessed for their effect on swelling and release. The highest swelling ratio (6413 %) and drug release (84.12 %) occurred at pH 1.2 compared to pH 7.4 (swelling ratio of 2721 % and drug release of 79.36 %) in 48 h. The hydrogels exhibited high porosity (84.23 %) and biodegradation (9.30 % in 7 days). In vitro hemolysis tests have demonstrated the compatibility of the hydrogel with blood. CCK-8 assay confirmed the biocompatibility of the synthesized hydrogel using osteoblasts and RIN-m5f cells. LSD exhibited good anti-inflammatory activity when loaded into hydrogels after being subjected to protein denaturation experiments. Moreover, LSD-loaded hydrogels have good antioxidant and antibacterial properties.


Assuntos
Preparações de Ação Retardada , Liberação Controlada de Fármacos , Galactanos , Hidrogéis , Mananas , Gomas Vegetais , Gomas Vegetais/química , Galactanos/química , Galactanos/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Mananas/química , Mananas/farmacologia , Glycyrrhiza/química , Humanos , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Portadores de Fármacos/química , Antibacterianos/farmacologia , Antibacterianos/química , Linhagem Celular
14.
Genes (Basel) ; 15(5)2024 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-38790201

RESUMO

Wintergrazer-70 and Ganyin No1 are high-yield forage varieties suitable for cultivation in high-altitude areas of Tibet (4300 m above sea level). Ganyin No1 was developed from Wintergrazer-70, with the latter serving as its parent variety. Ganyin No1 was identified as a spring variety, and subsequent RNA sequencing was conducted. RNA sequencing analysis identified 4 differentially expressed genes related to vernalization and 28 genes related to photoperiod regulation. The Sc7296g5-i1G3 gene is related to the flowering inhibition of rye, which may be related to the phenotypic difference in the Ganyin No1 variety in winter and spring. This finding provides valuable insights for future research on Ganyin No1, especially in addressing feed shortages in Tibet during winter and spring.


Assuntos
Altitude , Estações do Ano , Secale , Secale/genética , Regulação da Expressão Gênica de Plantas , Análise de Sequência de RNA/métodos , Mutação , Tibet , Proteínas de Plantas/genética
15.
Front Plant Sci ; 14: 1090204, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36778684

RESUMO

There are still uncertainties on the impacts of season-non-uniform-warming on plant precipitation use efficiency (PUE) and its temporal stability (PUEstability) in alpine areas. Here, we examined the changes of PUE and PUEstability under two scenes of non-growing/growing season non-uniform-warming (i.e., GLNG: growing-season-warming lower than non-growing-season-warming; GHNG: growing-season-warming higher than non-growing-season-warming) based on a five-year non-uniform-warming of non-growing/growing season experiment. The GLNG treatment increased PUE by 38.70% and reduced PUEstability by 50.47%, but the GHNG treatment did not change PUE and PUEstability. This finding was mainly due to the fact that the GLNG treatment had stronger influences on aboveground biomass (AGB), non-growing-season soil moisture (SMNG), temporal stability of AGB (AGBstability), temporal stability of non-growing-season air temperature (T a_NG_stability), temporal stability of growing-season vapor pressure deficit (VPDG_stability) and temporal stability of start of growing-season (SGSstability). Therefore, the warming scene with a higher non-growing-season-warming can have greater influences on PUE and PUEstability than the warming scene with a higher growing-season-warming, and there were possibly trade-offs between plant PUE and PUEstability under season-non-uniform-warming scenes in the alpine meadow.

16.
Plants (Basel) ; 12(17)2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37687264

RESUMO

The uncertain responses of aboveground net primary productivity (ANPP) and plant diversity to climate warming and increased precipitation will limit our ability to predict changes in vegetation productivity and plant diversity under future climate change and further constrain our ability to protect biodiversity and ecosystems. A long-term experiment was conducted to explore the responses of ANPP, plant species, phylogenetic α-diversity, and community composition to warming and increased precipitation in an alpine meadow of the Northern Tibet from 2014 to 2019. Coverage, height, and species name were obtained by conventional community investigation methods, and ANPP was obtained using observed height and coverage. Open-top chambers with two different heights were used to simulate low- and high-level climate warming. The low- and high-level increased precipitation treatments were achieved by using two kinds of surface area funnel devices. The high-level warming reduced sedge ANPP (ANPPsedge) by 62.81%, species richness (SR) by 21.05%, Shannon by 13.06%, and phylogenetic diversity (PD) by 14.48%, but increased forb ANPP (ANPPforb) by 56.65% and mean nearest taxon distance (MNTD) by 33.88%. Species richness, Shannon, and PD of the high-level warming were 19.64%, 9.67%, and 14.66% lower than those of the low-level warming, respectively. The high-level warming-induced dissimilarity magnitudes of species and phylogenetic composition were greater than those caused by low-level warming. The low- rather than high-level increased precipitation altered species and phylogenetic composition. There were significant inter-annual variations of ANPP, plant species, phylogenetic α-diversity and community composition. Therefore, climate warming and increased precipitation had non-linear effects on ANPP and plant diversity, which were due to non-linear changes in temperature, water availability, and/or soil nutrition caused by warming and increased precipitation. The inter-annual variations of ANPP and plant diversity were stronger than the effects of warming and especially increased precipitation on ANPP and plant diversity. In terms of plant diversity conservation and related policy formulation, we should pay more attention to regions with greater warming, at least for the northern Tibet grasslands. Besides paying attention to the responses of ANPP and plant diversity to climate change, the large inter-annual changes of ANPP and plant diversity should be given great attention because the large inter-annual variation indicates the low temporal stability of ANPP and plant diversity and thus produces great uncertainty for the development of animal husbandry.

17.
J Funct Biomater ; 14(5)2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37233388

RESUMO

Oxidants play a crucial role in the development of oxidative stress, which is linked to disease progression. Ellagic acid is an effective antioxidant with applications in the treatment and prevention of several diseases, since it neutralizes free radicals and reduces oxidative stress. However, it has limited application due to its poor solubility and oral bioavailability. Since ellagic acid is hydrophobic, it is difficult to load it directly into hydrogels for controlled release applications. Therefore, the purpose of this study was to first prepare inclusion complexes of ellagic acid (EA) with hydroxypropyl-ß-cyclodextrin and then load them into carbopol-934-grafted-2-acrylamido-2-methyl-1-propane sulfonic acid (CP-g-AMPS) hydrogels for orally controlled drug delivery. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) were used to validate ellagic acid inclusion complexes and hydrogels. There was slightly higher swelling and drug release at pH 1.2 (42.20% and 92.13%) than at pH 7.4 (31.61% and 77.28%), respectively. Hydrogels had high porosity (88.90%) and biodegradation (9.2% per week in phosphate-buffered saline). Hydrogels were tested for their antioxidant properties in vitro against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Additionally, the antibacterial activity of hydrogels was demonstrated against Gram-positive bacterial strains (Staphylococcus aureus and Escherichia coli) and Gram-negative bacterial strains (Pseudomonas aeruginosa).

18.
Sci Total Environ ; 876: 162641, 2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-36921851

RESUMO

Fostering crop-livestock integration via crop-forage rotation provides opportunities to cope with land degradation, feed deficit, and agropastoral sustainability. Farmers' preferences for forage options are influenced by economic benefit, environmental preference, and productive performance. However, there is little information available on evaluating multiple trade-offs of forage systems for the design of crop-forage rotations. Here, we performed a comprehensive evaluation to compare the economic, environmental, and productive indicators of five typical forage systems in terms of habitat conditions, soil ecosystem services, economic profit, and forage yield and nutritive value on the southern Tibetan Plateau. Alfalfa pasture and silage corn were mostly cultivated in lower altitudes, with more abundant precipitation, and higher growing degree days. Soil carbon and nitrogen accumulation were significantly higher in perennial alfalfa than in the other forage systems. The relative feed value of alfalfa pasture was also evidently greater than the other forage systems, whereas the yield of silage corn was among the highest. Alfalfa pasture presented superior economic benefits compared to the others. But the alfalfa pasture over six years showed a significant decrease in soil carbon and nitrogen storage, net present value, and yield. Forage systems generally have more soil carbon accumulation, but only forage legumes are more likely to positively affect soil nitrogen retention compared to cereal croplands. The trade-offs among economic, environmental, and productive indicators demonstrated that annual forage systems (silage corn, forage oat, and ryegrass) met productive target rather than environmental and economic objectives, while perennial alfalfa showed synergies among the three goals. These findings indicate that integrating crop-forage rotation, particularly introducing legume forages into farming systems is an adaptive option for crop-livestock integration on the southern Tibetan Plateau. Given the large topographic variation, suitable crop-forage systems should be designed for the heterogeneous Yarlung Zangbo River valleys. Among them, alfalfa-silage corn intercropping is recommended as a promising system to meet both productivity and profitability.


Assuntos
Ecossistema , Gado , Animais , Indicadores Ambientais , Tibet , Solo , Zea mays , Medicago sativa , Carbono , Nitrogênio
19.
Gels ; 9(3)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36975695

RESUMO

Puerarin has been reported to have anti-inflammatory, antioxidant, immunity enhancement, neuroprotective, cardioprotective, antitumor, and antimicrobial effects. However, due to its poor pharmacokinetic profile (low oral bioavailability, rapid systemic clearance, and short half-life) and physicochemical properties (e.g., low aqueous solubility and poor stability) its therapeutic efficacy is limited. The hydrophobic nature of puerarin makes it difficult to load into hydrogels. Hence, hydroxypropyl-ß-cyclodextrin (HP-ßCD)-puerarin inclusion complexes (PIC) were first prepared to enhance solubility and stability; then, they were incorporated into sodium alginate-grafted 2-acrylamido-2-methyl-1-propane sulfonic acid (SA-g-AMPS) hydrogels for controlled drug release in order to increase bioavailability. The puerarin inclusion complexes and hydrogels were evaluated via FTIR, TGA, SEM, XRD, and DSC. Swelling ratio and drug release were both highest at pH 1.2 (36.38% swelling ratio and 86.17% drug release) versus pH 7.4 (27.50% swelling ratio and 73.25% drug release) after 48 h. The hydrogels exhibited high porosity (85%) and biodegradability (10% in 1 week in phosphate buffer saline). In addition, the in vitro antioxidative activity (DPPH (71%), ABTS (75%), and antibacterial activity (Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) indicated the puerarin inclusion complex-loaded hydrogels had antioxidative and antibacterial capabilities. This study provides a basis for the successful encapsulation of hydrophobic drugs inside hydrogels for controlled drug release and other purposes.

20.
Environ Sci Pollut Res Int ; 30(33): 80378-80392, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37296251

RESUMO

In order to study the detoxification effect of microbial exopolysaccharides (EPS) on the heavy metal cadmium (Cd2+), this study took an EPS-producing Serratia fonticola CPSE11 (NZ_CP050171.1) isolated from Codonopsis pilosula root as the research object. The whole genome and EPS synthesis gene clusters of this strain were predicted and analyzed, the adsorption kinetics of EPS on Cd2+ were studied by using pseudo-first-order and second-order kinetic equations, the isothermal adsorption curves were simulated and analyzed by using the Langmuir isothermal adsorption equation, and the effects of Cd2+ and EPS on the growth of C. pilosula were explored by seed germination experiment and hydroponic experiment. The analysis revealed that this strain contained three gene clusters related to EPS synthesis, and the metabolic pathway for EPS synthesis was obtained on the basis of the whole genome analysis and microbial physiological metabolism. The molecular weight and monosaccharide composition of EPS were determined by HPLC analysis, which showed that EPS consisted of mannose, glucosamine, rhamnose, galactosamine, glucose, and galactose with a molar ratio of 1:1.74:4.57:3.96:14.04:10.28, with the molecular weight of 366,316.09 kDa. The adsorption process of EPS on Cd2+ was in accordance with the second-order kinetic model, and the results of seed germination experiments showed that EPS could promote seed germination and improve seed activity. In the hydroponic experiment, high concentration of Cd2+ (15 mg/L) caused toxic symptoms in C. pilosula, while the addition of EPS reduced the toxic effect of Cd2+ on C. pilosula, and the plant growth was significantly improved.


Assuntos
Codonopsis , Metais Pesados , Cádmio , Monossacarídeos/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA