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1.
Sci Total Environ ; 946: 174054, 2024 Jun 17.
Article de Anglais | MEDLINE | ID: mdl-38897466

RÉSUMÉ

Up to date, most studies reported that degradation is worsened in the grassland ecosystems of Inner Mongolia and adjacent regions as a result of intensified grazing. This seems to be scientific when considering the total forage or total above-ground biomass as a degradation indicator, but it does not hold true in terms of soil organic carbon density (SOCD). In this study, we quantified the changes of grassland ecosystem carbon stock in Inner Mongolia and adjacent regions from the 1980s to 2000s and identified the major drivers influencing these variations, using the National Grassland Resource Inventory and Soil Survey Dataset in 1980s and the Inventory data during 2002 to 2009 covering 624 sampling plots concerned vegetal traits and edaphic properties across the study region. The result indicated that the above-, below-ground and total vegetation biomass declined from the 1980s to 2000s by ∼ 10 %. However, total forage production increased by 6.72 % when considering livestock intake. SOCD remained stable despite a 67 % increase in grazing intensity. A generalized linear model (GLIM) analysis suggested that an increase in grazing intensity from the 1980s to 2000s could only explain 1.04 % of the total biomass change, while changes in precipitation and temperature explained 17.7 % (p < 0.05) of total vegetation biomass (TVB) change. Meanwhile, SOCD change during 1980s - 2000s could be explained 10.08 % by the soil texture (p < 0.05) and <1.6 % by changes in climate and livestock. This implies that the impacts of climate change on grassland biomass are more significant than those of grazing utilization, and SOCD was resistant to both climate change and intensified grazing. Overall, intensified grazing did not result in significant negative impacts on the grassland carbon stocks in the study region during the 1980s and 2000s. The grassland ecosystems possess a mechanism to adjust their root-shoot ratio, enabling them to maintain resilience against grazing utilization.

2.
ACS Appl Mater Interfaces ; 16(3): 4045-4055, 2024 Jan 24.
Article de Anglais | MEDLINE | ID: mdl-38198227

RÉSUMÉ

The flame-retardant paper has gradually evolved into a necessary material in various industries as a result of the rising importance of fire safety, energy efficiency, and environmental preservation. Traditional cellulose paper requires the addition of a large amount of flame retardants to achieve flame retardancy, which poses a serious threat to mechanical quality and the environment. Therefore, there is an urgent need to develop inorganic fiber flame-retardant paper with good flexibility, high thermal stability, and inherent flame retardancy. Herein, inspired by the "brick-and-mortar" layered structure of nature nacre, we developed a layered composite paper with a unique alternating arrangement of organic-inorganic fibers by synergistically integrating environmentally sustainable basalt fiber (BF) and high-performance aramid nanofibers (ANFs) through a vacuum-assisted filtration process. The as-prepared ANFs/BF composite paper exhibited low thermal conductivity (0.024 W m-1 K-1), high tensile strength (54.22 MPa), and excellent flexibility. Thanks to its excellent thermal stability, the mechanical strength remains at a high level (92%) after heat treatment at 300 °C for 60 min. Furthermore, the peak heat release rate and smoke generation of ANFs/BF composite paper decreased by 44.6 and 95.3%, respectively. Therefore, the composite paper is promising for applications as a protective layer in flexible electronic devices, cables, and fire-retardant and high-temperature fields.

3.
Int J Biol Macromol ; 257(Pt 1): 128602, 2024 Feb.
Article de Anglais | MEDLINE | ID: mdl-38056749

RÉSUMÉ

Silicate scales are commonly incorporated into cellulose nanofiber (CNF) as functional fillers to enhance electrical insulation and UV-shielding properties. Nevertheless, the addition of substantial quantities of silicate scales in the quest for enhanced functional properties results in reduced interface bonding capability and compromised mechanical properties, thereby restricting their application. Here, inspired from nacre, layered composite paper with excellent mechanical strength, electrical insulation and UV-resistance properties was fabricated through vacuum assisted self-assembly using CNF, PVA and basalt scales (BS). Unlike the conventional blending strategy, the pre-mixed PVA and BS suspension facilitates the formation of Al-O-C bond, thereby enhancing the interfacial bonding between BS and CNF. Consequently, the composite paper (BS@PVA/PVA/CNF) containing 60 wt% BS demonstrates higher mechanical strength-approximately 140 % higher than that of BS/CNF composite paper, achieving a strength of 33.5 MPa. Additionally, it demonstrates enhanced dielectric properties, surpassing those of CNF paper by up to 107 %. Moreover, it exhibits robust ultraviolet-resistant aging performance, retaining ~87 % of its tensile strength after undergoing a simulated two-year aging period. As a result, this work presents a simple and innovative design strategy for enhancing interfacial bonding and optimizing layer structure, providing essential guidelines for large-scale production of high-performance insulation and aging-resistant composite paper.


Sujet(s)
Nacre , Cellulose , Silicates
4.
Brain Sci ; 13(10)2023 Sep 22.
Article de Anglais | MEDLINE | ID: mdl-37891726

RÉSUMÉ

The purpose of this study was to explore the resting-state functional connectivity (FC) changes among the pain matrix and other brain regions in herpes zoster (HZ) and postherpetic neuralgia (PHN) patients. Fifty-four PHN patients, 52 HZ patients, and 54 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans. We used a seed-based FC approach to investigate whether HZ and PHN patients exhibited abnormal FC between the pain matrix and other brain regions compared to HCs. A random forest (RF) model was constructed to explore the feasibility of potential neuroimaging indicators to distinguish the two groups of patients. We found that PHN patients exhibited decreased FCs between the pain matrix and the putamen, superior temporal gyrus, middle frontal gyrus, middle cingulate gyrus, amygdala, precuneus, and supplementary motor area compared with HCs. Similar results were observed in HZ patients. The disease durations of PHN patients were negatively correlated with those aforementioned impaired FCs. The results of machine learning experiments showed that the RF model combined with FC features achieved a classification accuracy of 75%. Disrupted FC among the pain matrix and other regions in HZ and PHN patients may affect multiple dimensions of pain processing.

5.
ACS Appl Mater Interfaces ; 15(29): 35495-35506, 2023 Jul 26.
Article de Anglais | MEDLINE | ID: mdl-37439589

RÉSUMÉ

In the field of electromagnetic shielding, it has become an important trend to manufacture thinner and better-performing electromagnetic interference (EMI) shielding materials. However, EMI shielding materials that are recyclable and resistant to extreme environments are of great significance for sustainable development and expanding their application areas. In this study, a composite paper with a "rebar-concrete" layered structure through the vacuum-assisted filtration approach by utilizing basalt fibers (BF) and aramid nanofibers (ANFs) with excellent temperature resistance and multiwalled carbon nanotubes with high electrical conductivity was prepared. The composite paper not only delivers a high electrical conductivity of 15.9 S cm-1 and a high electromagnetic interference shielding efficiency (EMI SE) of 24.6 dB but also exhibits a high specific shielding efficiency (SSE/t) of 12,504 dB cm2 g-1 at a thickness of 48 µm. Thanks to the excellent thermal stability of basalt fibers and aramid nanofibers, the composite paper exhibits long-term stable EMI shielding performance and structural integrity in various extreme environments, including fire, high/low temperature (-196 to 300 °C), and acid-base corrosion. Furthermore, the BF/ANF/CNT composite paper also shows excellent Joule heating performance, rapid electrothermal response, and good temperature controllability. Based on these excellent properties, the BF/ANF/CNT composite paper shows tremendous potential for practical applications to meet the requirements of various extreme environments.

6.
Vet Microbiol ; 284: 109826, 2023 Sep.
Article de Anglais | MEDLINE | ID: mdl-37421928

RÉSUMÉ

Pseudorabies virus (PRV) preferably invades neural tissue and various organs, whereupon may result in multisystemic lesions. Pyroptosis mediated by proteolytic cleavage of gasdermin D (GSDMD) by inflammatory caspases (caspase-1/4/5/11), is closely associated with the activation of inflammasomes, a multiprotein proinflammatory complex. However, further studies on the mechanisms regarding PRV-induced pyroptosis in its natural host are required. Herein, it is demonstrated that PRV infection triggered GSDMD- not GSDME-mediated pyroptosis in porcine alveolar macrophage cells, resulting in increased secretion of IL-1ß and LDH. During this process, caspase-1 was activated and participated in the cleaving of GSDMD. Interestingly, we found that the viral replication process or protein production is required to induce pyroptotic cell death. Also, our findings showed that PRV triggered NLRP3 inflammasome activation, which was associated with the production of reactive oxygen species (ROS) and potassium efflux. In addition to the NLRP3 inflammasome, the IFI16 inflammasome was also activated. Importantly, the NLRP3- and IFI16- inflammasomes were both involved in pyroptosis during PRV infection. Finally, we observed that the cleaved GSDMD, activated caspase-1, increased IFI16 levels, and elevated NLRP3 protein in PRV-infected tissues (brain and lung), supporting the occurrence of pyroptosis and the activation of NLRP3- and IFI16- inflammasome in PRV-infected pigs. This research advances our understanding of the PRV-mediated inflammatory response and cell death pathways, providing a deeper knowledge of effective treatments for pseudorabies.


Sujet(s)
Herpèsvirus porcin de type 1 , Inflammasomes , Animaux , Suidae , Inflammasomes/métabolisme , Protéine-3 de la famille des NLR contenant un domaine pyrine/génétique , Protéine-3 de la famille des NLR contenant un domaine pyrine/métabolisme , Pyroptose/physiologie , Herpèsvirus porcin de type 1/métabolisme , Caspases , Caspase-1/métabolisme
7.
Adv Sci (Weinh) ; 10(27): e2302371, 2023 Sep.
Article de Anglais | MEDLINE | ID: mdl-37485624

RÉSUMÉ

The rapid development of modern electrical equipment has led to urgent demands for electrical insulating materials with mechanical reliability and excellent dielectric properties. Herein, basalt nanosheets (BSNs) with high aspect ratios (≈780.1) are first exfoliated from basalt scales (BS) through a reliable chemical/mechanical approach. Meanwhile, inspired by the layered architecture of natural nacre, nacre-mimetic composite nanopapers are reported containing a 3D aramid nanofibers (ANF) framework as a matrix and BSNs as ideal building blocks through vacuum-assisted filtration. The as-prepared ANF-BSNs composite nanopapers exhibit considerably enhanced mechanical properties with ultralow BSNs content. These superiorities are wonderfully integrated with exceptional dielectric breakdown strength, prominent volume resistivity, and extremely low dielectric constant and loss, which are far superior to conventional nacre-mimetic composite nanopapers. Notably, the tensile strength and breakdown strength of ANF-BSNs composite nanopapers with a mere 1.0 wt% BSNs reach 269.40 MPa and 77.91 kV mm-1 , respectively, representing an 87% and 133% increase compared to those of the control ANF nanopaper. Their properties are superior to those of previously reported nacre-mimetic composite nanopapers and commercial insulating micropapers, indicating that ANF-BSNs composite nanopapers are a highly promising electrical insulating material for miniaturized high-power electrical equipment.

8.
Vet Res ; 54(1): 21, 2023 Mar 14.
Article de Anglais | MEDLINE | ID: mdl-36918936

RÉSUMÉ

The alphaherpesvirus pseudorabies virus (PRV) is the causative agent of pseudorabies, responsible for severe economic losses to the swine industry worldwide. The interferon-inducible GTPase guanylate-binding protein 1 (GBP1) exhibits antiviral immunity. Our findings show that there is a robust upregulation in the expression of porcine GBP1 during PRV infection. GBP1 knockout promotes PRV infection, while GBP1 overexpression restricts it. Importantly, we found that GBP1 impeded the normal structure of actin filaments in a GTPase-dependent manner, preventing PRV virions from reaching the nucleus. We also discovered that viral US3 protein bound GBP1 to interfere with its GTPase activity. Finally, the interaction between US3 and GBP1 requires US3 serine/threonine kinase activity sites and the GTPase domain (aa 1 to 308) of GBP1. Taken together, this study offers fresh perspectives on how PRV manipulates the host's antiviral immune system.


Sujet(s)
Herpèsvirus porcin de type 1 , Maladie d'Aujeszky , Maladies des porcs , Suidae , Animaux , Herpèsvirus porcin de type 1/physiologie , Cytosquelette d'actine/métabolisme , Protéines virales/métabolisme , dGTPases/métabolisme , Antiviraux , Maladies des porcs/métabolisme
9.
Microb Ecol ; 85(1): 221-231, 2023 Jan.
Article de Anglais | MEDLINE | ID: mdl-35043220

RÉSUMÉ

Soil microorganisms play key roles in terrestrial biogeochemical cycles and ecosystem functions. However, few studies address how long-term nitrogen (N) addition gradients impact soil bacterial and fungal diversity and community composition simultaneously. Here, we investigated soil bacterial and fungal diversity and community composition based on a long-term (17 years) N addition gradient experiment (six levels: 0, 2, 4, 8, 16, 32 gN m-2 year-1) in temperate grassland, using the high-throughput Illumina MiSeq sequencing. Results showed that both soil bacterial and fungal alpha diversity responded nonlinearly to the N input gradient and reduced drastically when the N addition rate reached 32 g N m-2 year-1. The relative abundance of soil bacterial phyla Proteobacteria increased and Acidobacteria decreased significantly with increasing N level. In addition, the relative abundance of bacterial functional groups associated with aerobic ammonia oxidation, aerobic nitrite oxidation, nitrification, respiration of sulfate and sulfur compounds, and chitinolysis significantly decreased under the highest N addition treatment. For soil fungi, the relative abundance of Ascomycota increased linearly along the N enrichment gradient. These results suggest that changes in soil microbial community composition under elevated N do not always support the copiotrophic-oligotrophic hypothesis, and some certain functional bacteria would not simply be controlled by soil nutrients. Further analysis illustrated that reduced soil pH under N addition was the main factor driving variations in soil microbial diversity and community structure in this grassland. Our findings highlight the consistently nonlinear responses of soil bacterial and fungal diversity to increasing N input and the significant effects of soil acidification on soil microbial communities, which can be helpful for the prediction of underground ecosystem processes in light of future rising N deposition.


Sujet(s)
Microbiote , Sol , Sol/composition chimique , Prairie , Microbiologie du sol , Bactéries/génétique , Champignons/génétique , Concentration en ions d'hydrogène
10.
Bioresour Technol ; 363: 127876, 2022 Nov.
Article de Anglais | MEDLINE | ID: mdl-36049712

RÉSUMÉ

The condensation of lignin under acidic conditions inhibited the subsequent value-added utilization of lignin, and the condensed lignin covered the biomass surface. Here, a method of benzenesulfonic acid pretreatment combined with nucleophilic reagents promoted pyrolytic saccharification and lignin hydrogenation was reported. The anhydrosugar content in the pyrolysis bio-oil increased from 66.91% to 69.00%, 72.88%, and 72.16% via adding methanol, propionaldehyde, 3-hydroxylic-2-naphthoic acid, respectively. The characterization of the biomass surface structure and the calculation of bond lengths indicated that carbonium ions prefer to bind with the added nucleophilic reagent rather than the lignin fragment. Furthermore, the quenching of the carbonium ions preserved the ß-O-4 bond, as demonstrated in 2D NMR. In the subsequent hydrogenation reaction, it was found that methanol facilitated the production of lignin monomer. The calculation also revealed that the quenching of the carbonium ions with methanol reduced the bond-breaking energy of the ß-O-4 bond.


Sujet(s)
Lignine , Pyrolyse , Biomasse , Indicateurs et réactifs , Ions , Lignine/composition chimique , Méthanol
11.
Bioresour Technol ; 363: 127989, 2022 Nov.
Article de Anglais | MEDLINE | ID: mdl-36126848

RÉSUMÉ

In this study, the hydrothermal and photocatalytic synergistic pretreatment for improving the full component utilization of corn stalk based on lignin first biorefining was employed to generate carbohydrates and obtain modified lignin. The results showed that the highest lignin removal ratio (40.70 %) and cellulose retention ratio (92.64 %) were obtained due to the smallest energy gap (6.05 eV) and the largest penetration distance (1.73 Å) between GVL and the lignin. And the yield of carbohydrates increased from 1.95 % to 58.17 % after hydrothermal pretreatment at 180 ℃. Furthermore, the modified lignin enhanced the flocculation effect, resulting in the increase of the removal of safranine-T by 6 times. In addition, the chemical and physical properties of modified lignin were studied and the mechanism of photocatalysis modification was explored. The research provides a new pretreatment method for the utilization of biomass and simultaneously achieves carbohydrate enrichment in bio-oil and purification of dye wastewater.


Sujet(s)
Lignine , Zea mays , Biomasse , Cellulose/composition chimique , Hydrolyse , Lignine/composition chimique , Eaux usées , Zea mays/composition chimique
12.
Front Oncol ; 12: 934108, 2022.
Article de Anglais | MEDLINE | ID: mdl-35865467

RÉSUMÉ

Objective: To compare the performance of different imaging classifiers in the prospective diagnosis of prostate diseases based on multiparameter MRI. Methods: A total of 238 patients with pathological outcomes were enrolled from September 2019 to July 2021, including 142 in the training set and 96 in the test set. After the regions of interest were manually segmented, decision tree (DT), Gaussian naive Bayes (GNB), XGBoost, logistic regression, random forest (RF) and support vector machine classifier (SVC) models were established on the training set and tested on the independent test set. The prospective diagnostic performance of each classifier was compared by using the AUC, F1-score and Brier score. Results: In the patient-based data set, the top three classifiers of combined sequences in terms of the AUC were logistic regression (0.865), RF (0.862), and DT (0.852); RF "was significantly different from the other two classifiers (P =0.022, P =0.005), while logistic regression and DT had no statistical significance (P =0.802). In the lesions-based data set, the top three classifiers of combined sequences in terms of the AUC were RF (0.931), logistic regression (0.922) and GNB (0.922). These three classifiers were significantly different from. Conclusion: The results of this experiment show that radiomics has a high diagnostic efficiency for prostate lesions. The RF classifier generally performed better overall than the other classifiers in the experiment. The XGBoost and logistic regression models also had high classification value in the lesions-based data set.

14.
Bioresour Technol ; 344(Pt A): 126143, 2022 Jan.
Article de Anglais | MEDLINE | ID: mdl-34678449

RÉSUMÉ

Microalgae are considered as a promising alternative to fossil fuels due to their ease of cultivation, short growth cycle and no occupation of cultivated land. In this study, N,N-Dimethylformamide (DMF) solvent was employed to assist hydrothermal pretreatment of Chlorella for coproduction of sugar, nitrogenous compounds and carbon dots (CDs). The effect of pretreatment conditions on the composition and pyrolysis bio-oil distribution of hydrothermal solid residues as well as CDs characteristic were investigated by varying the temperature (180-220 ℃) and reaction time (1-9 h). The results showed that pretreated residues had higher cellulose. And the yield of sugar and N-contained compounds reached 41.59% and 63.57% in the pyrolysis bio-oil of pretreated algae residues, respectively. Moreover, CDs obtained from hydrothermal solution fluoresced red under 365 nm excitation. The paper provides a new method for the complete utilization of microalgae.


Sujet(s)
Chlorella , Microalgues , Biocarburants , Carbone , N,N-Diméthyl-formamide , Composés de l'azote , Solvants , Sucres , Température
15.
Bioresour Technol ; 346: 126478, 2022 Feb.
Article de Anglais | MEDLINE | ID: mdl-34910973

RÉSUMÉ

The seawater electrochemical pretreatment (ECP) was employed to upgrade the bio-oil of corn stalk in the paper. The seawater and its simulants were used as electrolytes without additional reagents. Moreover, the effect of seawater ECP under different conditions on the products distribution of pyrolysis bio-oil of pretreated corn stalks was investigated. The results showed that pretreatment effectively deconstructed the lignin and made cellulose exposed. Especially, under the optimum conditions (3.5 wt% NaCl, 15 V and 4 h), most of lignin was destroyed, and cellulose and hemicellulose were remained in residual solids. Furthermore, the levoglucosan and furfural were enriched in the pyrolysis bio-oil of corn stalk after seawater ECP, reaching 23.22 % and 14.14 %, respectively. Overall, this work presented a novel and green pretreatment process to optimize the components and structure of corn stalks as well as upgrade the bio-oil of corn stalk pyrolysis.


Sujet(s)
Furfural , Pyrolyse , Biomasse , Glucose/analogues et dérivés , Lignine , Eau de mer , Zea mays
16.
Sci Total Environ ; 757: 143768, 2021 Feb 25.
Article de Anglais | MEDLINE | ID: mdl-33229097

RÉSUMÉ

Steppe soils are important biological sinks for atmospheric methane (CH4), but the strength of CH4 uptake remains uncertain due to large spatiotemporal variation and the lack of in situ measurements at regional scale. Here, we report the seasonal and spatial patterns of CH4 uptake across a 1200 km transect in arid and semi-arid steppe ecosystems in Inner Mongolia, ranging from meadow steppe in the east plain to typical and desert steppes on the west plateau. In general, seasonal patterns of CH4 uptake were site specific, with unimodal seasonal curves in meadow and typical steppes and a decreasing seasonal trend in desert steppe. Soil moisture was the dominant factor explaining the seasonal patterns of CH4 uptake, and CH4 uptake rate decreased with an increase in soil moisture. Across the transect, CH4 uptake showed a skewed unimodal spatial pattern, with the peak rate observed in the typical steppe sites and with generally higher uptake rates in the west plateau than in the east plain. Soil moisture, together with soil temperature, soil total carbon, and aboveground plant biomass, were the main drivers of the regional patterns of CH4 uptake rate. These findings are important for model development to more precisely estimate the soil CH4 sink capacity in arid and semi-arid regions.

17.
Ying Yong Sheng Tai Xue Bao ; 31(10): 3473-3479, 2020 Oct.
Article de Chinois | MEDLINE | ID: mdl-33314837

RÉSUMÉ

Shading is one of the important strategies to protect seedlings of Paeonia lactiflora. The effects of shading treatments on seedling growth and mineral accumulation of Duolun P. lactiflora were investigated in a greenhouse experiment to provide guidance for P. lactiflora cultivation. One week after emergence, seedlings were treated with 20%, 40%, 60% or 80% shading for two months, with no-shading as the control (CK). The results showed that shading treatments significantly increased plant height by 19.9%, 31.1%, 52.9%, and 63.7%, respectively. However, shading significantly reduced the root mass ratio and root to shoot ratio by 21.5%, 23.6%, 29.2%, 41.8% and 40.6%, 44.0%, 50.9%, 63.2%, respectively. Moreover, 40%, 60% and 80% shading significantly increased specific leaf area by 77.0%, 84.1% and 65.2%, and significantly increased chlorophyll content by 92.3%, 128.7%, 98.1%, and increased carotenoid content by 86.9%, 113.1% and 90.5%, respectively. The treatments of 40%, 60%, and 80% shading significantly decreased root biomass by 61.4%, 74.3% and 78.6%, respectively. Compared with CK, 20%, 40% and 80% shading, the 60% shading treatment increased root phosphorus content by 245.7%, 65.9%, 40.5% and 10.3%, increased potassium content by 102.9%, 131.7%, 57.0%, 63.3% and magnesium content by 131.3%, 55.1%, 40.4%, 7.7%, respectively. 60% shading was an appropriate shading intensity for P. lactiflora seedling cultivation based on local conditions in Duolun.


Sujet(s)
Paeonia , Plant , Chlorophylle , Minéraux , Feuilles de plante
18.
BMC Microbiol ; 20(1): 65, 2020 03 24.
Article de Anglais | MEDLINE | ID: mdl-32209070

RÉSUMÉ

BACKGROUND: It has recently been reported that intermittent fasting shapes the gut microbiota to benefit health, but this effect may be influenced to the exact fasting protocols. The purpose of this study was to assess the effects of different daily fasting hours on shaping the gut microbiota in mice. Healthy C57BL/6 J male mice were subjected to 12, 16 or 20 h fasting per day for 1 month, and then fed ad libitum for an extended month. Gut microbiota was analyzed by 16S rRNA gene-based sequencing and food intake was recorded as well. RESULTS: We found that cumulative food intake was not changed in the group with 12 h daily fasting, but significantly decreased in the 16 and 20 h fasting groups. The composition of gut microbiota was altered by all these types of intermittent fasting. At genus level, 16 h fasting led to increased level of Akkermansia and decreased level of Alistipes, but these effects disappeared after the cessation of fasting. No taxonomic differences were identified in the other two groups. CONCLUSIONS: These data indicated that intermittent fasting shapes gut microbiota in healthy mice, and the length of daily fasting interval may influence the outcome of intermittent fasting.


Sujet(s)
Bactéries/classification , Jeûne , ARN ribosomique 16S/génétique , Analyse de séquence d'ADN/méthodes , Animaux , Bactéries/génétique , Bactéries/isolement et purification , ADN bactérien/génétique , ADN ribosomique/génétique , Microbiome gastro-intestinal , Séquençage nucléotidique à haut débit , Mâle , Souris , Souris de lignée C57BL , Phylogenèse
19.
Biol Trace Elem Res ; 193(2): 548-554, 2020 Feb.
Article de Anglais | MEDLINE | ID: mdl-30997668

RÉSUMÉ

Roots of wild Paeonia lactiflora are often used as herbs in traditional Chinese medicine. In this study, the contents of potassium (K), calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) and the concentrations of three active ingredients such as paeoniflorin (PF), catechin (CA) and benzoic acid (BA) in roots of wild P. lactiflora collected from Duolun County of Inner Mongolia in China were evaluated. The results showed that the mean contents of eight elements followed the following order: Ca > K > P > Mg > Fe > Zn > Mn > Cu, and the concentrations of three active ingredients decreased in the order: PF > CA > BA. It was found that PF concentration was positively correlated with the contents of Fe and Mn. However, the concentration of CA was linearly decreased with Mg content. Moreover, BA concentration showed positive linear dependence upon the contents of P and Mn. Results of stepwise regression analyses showed that 39.2% of the variance in PF concentration could be explained by Fe content, whereas 28.1% of the CA concentration changes could be explained by Mg content; moreover, 42.5% of the variance in BA concentration could be accounted for by the combination of Mn and P contents. In a word, the concentrations of active ingredients in roots of P. lactiflora can be changed by adjusting mineral elements levels in roots to meet the need of appropriate quality control of P. lactiflora.


Sujet(s)
Éléments , Minéraux/analyse , Paeonia/composition chimique , Racines de plante/composition chimique , Acide benzoïque/analyse , Catéchine/analyse , Chine , Glucosides/analyse , Fer/analyse , Magnésium/analyse , Manganèse/analyse , Monoterpènes/analyse , Paeonia/croissance et développement , Phosphore/analyse , Racines de plante/croissance et développement , Analyse de régression , Zinc/analyse
20.
Glob Chang Biol ; 26(2): 960-970, 2020 02.
Article de Anglais | MEDLINE | ID: mdl-31529564

RÉSUMÉ

Livestock grazing often alters aboveground and belowground communities of grasslands and their mediated carbon (C) and nitrogen (N) cycling processes at the local scale. Yet, few have examined whether grazing-induced changes in soil food webs and their ecosystem functions can be extrapolated to a regional scale. We investigated how large herbivore grazing affects soil micro-food webs (microbes and nematodes) and ecosystem functions (soil C and N mineralization), using paired grazed and ungrazed plots at 10 locations across the Mongolian Plateau. Our results showed that grazing not only affected plant variables (e.g., biomass and C and N concentrations), but also altered soil substrates (e.g., C and N contents) and soil environment (e.g., soil pH and bulk density). Grazing had strong bottom-up effects on soil micro-food webs, leading to more pronounced decreases at higher trophic levels (nematodes) than at lower trophic levels (microbes). Structural equation modeling showed that changes in plant biomass and soil environment dominated grazing effects on microbes, while nematodes were mainly influenced by changes in plant biomass and soil C and N contents; the grazing effects, however, differed greatly among functional groups in the soil micro-food webs. Grazing reduced soil C and N mineralization rates via changes in plant biomass, soil C and N contents, and soil environment across grasslands on the Mongolian Plateau. Spearman's rank correlation analysis also showed that grazing reduced the correlations between functional groups in soil micro-food webs and then weakened the correlation between soil micro-food webs and soil C and N mineralization. These results suggest that changes in soil micro-food webs resulting from livestock grazing are poor predictors of soil C and N processes at regional scale, and that the relationships between soil food webs and ecosystem functions depend on spatial scales and land-use changes.


Sujet(s)
Écosystème , Sol , Animaux , Biomasse , Chaine alimentaire , Prairie , Herbivorie
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