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1.
Exp Ther Med ; 27(6): 250, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38682113

RESUMO

Osteogenesis is a complex process of bone formation regulated by various factors, yet its underlying molecular mechanisms remain incompletely understood. The present study aimed to investigate the role of S100A16, a novel member of the S100 protein family, in the osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) and uncover a novel Smad4-mitogen-activated protein kinase (MAPK)/Jun N-terminal kinase (JNK) signaling axis. In the present study, the expression level of S100A16 in bone tissues and BMSCs from ovariectomized rats was evaluated and then the impact of S100A16 silencing on osteogenic differentiation was examined. Increased S100A16 expression was observed in bone tissues and BMSCs from ovariectomized rats, and S100A16 silencing promoted osteogenic differentiation. Further transcriptomic sequencing revealed that the Smad4 pathway was involved in S100A16 silencing-induced osteogenesis. The results of western blot analysis revealed that S100A16 overexpression not only downregulated Smad4 but also activated MAPK/JNK signaling, which was validated by treatment with MAPK and JNK inhibitors U0126 and SP600125. Overall, in the present study, the novel regulatory factors influencing osteogenic differentiation were elucidated and mechanistic insights that could aid in the development of targeted therapeutic strategies for patients with osteoporosis were provided.

2.
Ying Yong Sheng Tai Xue Bao ; 34(10): 2601-2609, 2023 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-37897266

RESUMO

We sieved soils from a Pinus massoniana plantation in the Three Gorges Reservoir area into four aggregate sizes, including aggregates of 2000-8000 µm (large macroaggregates), 1000-2000 µm (coarse aggregates), 250-1000 µm (small macroaggregates), and <250 µm (microaggregates). We analyzed the differences in the acidolyzable organic N components and net N mineralization of the aggregates under different N addition levels (30, 60, and 90 kg N·hm-2·a-1, representing by N30, N60 and N90, respectively). The results showed that net nitrification rate of the aggregates ranged from 0.30-3.42 mg N·kg-1 and accounted for more than 80% of net nitrogen mineralization. Compared with the control, addition of 30, 60, and 90 kg N·hm-2·a-1 increased total N by 24.1%-45.5%, 6.4%-34.3%, and 7.9%-42.4% in the large aggregates, coarse aggregate, small macroaggregates, and microaggregates, increased net N mineralization rate by 1.3-7.2, 1.4-6.6, and 1.8-12.9 times, but decreased the contents of available phosphorus by 9.3%-36.9%, 12.2%-56.7%, and 19.2%-61.9%, respectively. The contents of total acidolyzable N, soil organic matter, and rates of net ammonification, net nitrification, and net N mineralization increased as the aggregate size decreased, while available phosphorus contents showed an opposite trend. The levels of acid-hydrolyzable N components were ranked as acidolyzable amino acid N > acidolyzable ammonia N > acidolyzable unknown N> acidolyzable amino sugar N. Total N was the dominant contributor to the increases in acid-hydrolyzable N components. Results of stepwise multiple regression analyses showed that acidoly-zable amino acid N and acidolyzable amino sugar N were predictors of net ammonification rate. Acidolyzable amino sugar N, acidolyzable amino acid N, and acidolyzable ammonia N were predictors of net nitrification, net nitrogen mineralization rate, and net nitrogen mineralization accumulation. The physical structure of aggregates was associa-ted with soil net N mineralization. Addition of N increased the contents and bioavailability of acidolyzable organic N, a large amount of which contributed to soil organic matter levels and the decrease in available phosphorus.


Assuntos
Nitrogênio , Pinus , Nitrogênio/análise , Amônia/análise , Solo/química , Fósforo/análise , China , Aminoácidos , Amino Açúcares , Carbono/análise
3.
Environ Res ; 231(Pt 2): 116081, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37164286

RESUMO

A large amount of stable soil organic matter (SOM) is derived from microbial necromass, which can be assessed by quantifying amino sugar biomarkers. Pinus massoniana Lamb. Plantations are widely distributed in China and play a vital role in forest carbon sequestration. However, the patterns of soil microbial residue remain poorly understood. In this study, amino sugars were used to characterize patterns of soil microbial residues at three soil depths (0-10, 10-20, and 20-30 cm) in P. massoniana plantations of different ages (young, middle-aged, near-mature, mature, and over-mature; denoted as YG, MD, NM, MT, and OM, respectively). In the topsoil (0-10 cm), the total nitrogen (TN) content of the OM forest was the highest, whereas the soil organic carbon (SOC) content of the MT forest was the highest. Consistent with changes in SOC and TN, total microbial residue content decreased with increasing soil depth. However, the total microbial residues C to SOC contribution increased considerably with increasing depth, suggesting that more SOC was derived from microbial residues in the subsoil than that from the topsoil. The fungal residue C to SOC contribution was higher than that of bacterial residue C. Total amino sugar content in the topsoil increased with increasing age, and MT and OM had a significantly higher content than that of other forests. At all soil depths, SOC and TN content predominantly determined microbial necromass, whereas soil microbial biomass content predominantly determined microbial necromass in the topsoil; soil pH predominantly determined microbial necromass in the 10-20 cm soil layer; and soil pH and Ca2+ content were the primary factors in the soil layer below 20 cm. The study provides valuable insights into controls of microbial-derived organic C could be applied in Earth system studies for predicting SOC dynamics in forests.


Assuntos
Pinus , Solo , Solo/química , Carbono/análise , Microbiologia do Solo , Florestas , China , Nitrogênio/análise
4.
Front Plant Sci ; 13: 1048153, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36452109

RESUMO

Increasing atmospheric nitrogen (N) deposition has a profound impact on the ecosystem functions and processes. Fine root decomposition is an important pathway for the reentry of nutrients into the soil. However, the effect of N addition on root decomposition and its potential mechanism is not well understood with respect to root branch orders. In this study, we conducted a 30-month decomposition experiment of fine roots under different concentrations of N addition treatments (0, 30, 60, and 90 kg N ha-1 year-1, respectively) in a typical Pinus massoniana plantation in the Three Gorges Reservoir Area of China. In the early stage of decomposition (0-18 months), N addition at all concentrations promoted the decomposition of fine roots, and the average decomposition rates of order 1-2, order 3-4, order 5-6 fine roots were increased by 13.54%, 6.15% and 7.96% respectively. In the late stage of decomposition (18-30 months), high N addition inhibited the decomposition of fine root, and the average decomposition rates of order 1-2, order 3-4, order 5-6 fine roots were decreased by 58.35%, 35.43% and 47.56% respectively. At the same time, N addition promoted the release of lignin, carbon (C), N, and phosphorus (P) in the early-stage, whereas high N addition inhibited the release of lignin, C, N, and the activities of lignin-degrading enzyme (peroxidase and polyphenol oxidase) in the late-stage. The decomposition constant (k) was significantly correlated with the initial chemical quality of the fine roots and lignin-degrading enzyme activities. The higher-order (order 3-4 and order 5-6) fine roots decomposed faster than lower-order (order 1-2) fine roots due to higher initial cellulose, starch, sugar, C concentrations and higher C/N, C/P, lignin/N ratios and lower N, P concentrations. In addition, low N (30 kg N ha-1 year-1) treatments decreased soil organic matter content, whereas high N (90 kg N ha-1 year-1) treatment had the opposite effect. All the N treatments reduced soil pH and total P content, indicating that increased N deposition may led to soil acidification. Our findings indicated that the effect of N addition on decomposition varied with the decomposition stages. The decomposition difference between the lower-order and higher-order fine roots were controlled strongly by the initial chemical quality of the fine roots. This study provides new insights into understanding and predicting possible changes in plant root decomposition and soil properties in the future atmospheric N deposition increase scenarios.

5.
Front Plant Sci ; 13: 1009109, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36570916

RESUMO

As a key component of terrestrial ecosystems, soil interacts directly with aboveground vegetation. Evaluating soil quality is therefore of great significance to comprehensively explore the interaction mechanism of this association. The purpose of this study was to fully understand the characteristics of aboveground vegetation, soil quality, and their potential coupling relationship among different forest types in Hunan Province, and to provide a theoretical basis for further exploring the mechanisms underlying soil-vegetation interactions in central China. We have set up sample plots of five kinds of forests (namely broad-leaved forest, coniferous forest, coniferous broad-leaved mixed forest, bamboo forest, and shrub forest) in Hunan Province. To explore the differences of vegetation characteristics and soil physical and chemical properties among the five stand types, variance analysis, principal component analysis, and regression analysis were used. Finally, we explored the coupling relationship between soil quality and aboveground vegetation characteristics of each forest. We found that there were significant differences in soil quality among the forest types, ranked as follows: shrub forest > bamboo forest > broad-leaved forest > mixed coniferous and broad-leaved forest > coniferous forest. In general, there was a negative correlation between vegetation richness and soil quality in the broad-leaved forest and the shrub forest, but they showed a positive correlation in the coniferous forest, the mixed coniferous and broad-leaved forest, and the bamboo forest. As a necessary habitat condition for aboveground vegetation, soil directly determines the survival and prosperity of plant species. These results indicated that for vegetation-soil dynamics in a strong competitive environment, as one aspect wanes the other waxes. However, in a weak competitive environment, the adverse relationship between vegetation and soil is less pronounced and their aspects can promote.

6.
Front Psychol ; 13: 900806, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35936333

RESUMO

This study proposed an extended theory of planned behavior (TPB) to examine the factors that influence pre-service teachers' intention to use technology-enabled learning, using constructivist pedagogical beliefs (CPB) and information and communication technologies (ICT) competencies as antecedent variables for attitudes, subjective norms (SNs), and perceived behavioral control. An online study was conducted with a random sample of pre-service teachers from 7 universities in China, and 811 validated questionnaires were obtained. The results showed that the extended TPB model explained 75% of the variance in intention; attitude, SNs, and perceived behavioral control had a positive and significant effect on intention. Furthermore, SNs had a positive and significant effect on attitude and perceived behavioral control. CPB were the antecedent variables for attitude, SNs, perceived behavioral control, and ICT competencies. ICT competencies were the antecedent variable for SNs and perceived behavioral control. Additionally, through multi-group analysis, this study found significant differences in path relationships between the lower and higher-grade groups. The effect of perceived behavioral control on intention diminished with increased grade level. The effect of SNs on perceived behavioral control reduced. The effect of CPB on attitude and perceived behavioral control on intention diminished. The effect of SNs on attitude increased. This study verified that adding the relationship between antecedent variables of theoretical factors and theoretical factors is an effective way to expand TPB and provided a reference for future studies to focus on the related intention of pre-service teachers. Furthermore, it recommends that Chinese universities should eliminate the hindering influence of CPB, ICT competencies, attitudes, SNs, and perceived behavioral control in the process of preparing pre-service teachers. They should also pay attention to the individual differences of students in different grades and the problems that arise in the existing training.

7.
Artigo em Inglês | MEDLINE | ID: mdl-35955027

RESUMO

Hybrid implementation of pedagogical models (PMs) helps to overcome the limitations of a single pedagogical model (PM) when it comes to improving student learning outcomes in physical education (PE). Empirical research on hybridizations has grown substantially in recent years, so the purpose of this study was to conduct a systematic review on the effects and mechanisms of different hybridizations on students' learning outcomes (i.e., motor, cognitive, affective, and social) in PE. Electronic databases, including ERIC, SCOPUS, EBSCO host, and Web of Science, were used to select intervention studies. After inclusion and exclusion criteria were applied, 17 high-quality studies, published in English peer-reviewed journals, were assessed. Results show that there were seven different hybrid models having impacts on students' learning outcomes, which could be divided into four categories: (1) game performance and technical skills; (2) understanding of tactics and decision-making abilities; (3) motivation, autonomy, and confidence; (4) interpersonal skills, cooperative learning ability, and responsibility. Length of implementation and teachers' familiarity were the main factors that limit the implementation on hybridizations. Future research should consider quasi-experiments with control groups of hybrids versus single models to figure out the advantages of the hybrid model over the single model; including more evidence from different schools, regions, and countries is necessary.


Assuntos
Aprendizagem , Educação Física e Treinamento , Humanos , Motivação , Instituições Acadêmicas , Estudantes/psicologia
8.
Chemosphere ; 305: 135430, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35772519

RESUMO

In this study, we investigated the recycling of Ni-Co-Mn cathode materials from spent LIBs by an acid leaching process using H3PO4 and HCl. The leaching liquor was then used to modify the biochar applied during the catalytic pyrolysis of the biomass. The addition of char catalysts decreased the maximum decomposition rate and shifted it to a lower temperature. Accordingly, the activation energy (Ea) of cellulose pyrolysis decreased from 140.86 kJ/mol to 83.55 kJ/mol (char-P) and 89.42 kJ/mol (char-Cl). The char catalysts enhanced the transformation of the large-molecule components to small-molecule gases during cellulose pyrolysis. The addition of both char-P and char-Cl decreased the anhydrosugar content and increased the hydrocarbon content, suggesting their high catalytic activities in converting anhydrosugars to hydrocarbons (e.g., long-chain alkanes). The anhydrosugar content decreased from 17.8% to 11.1%, while the furan content increased from 5.1% to 15.2% with the addition of char-P. The addition of char-Cl resulted in a lower content of furans (4.8%) and a higher content of hydrocarbons (40.1%), mostly because of the increase in alkanes and aromatic compounds. Therefore, these char catalysts could be used for biomass pyrolysis in terms of activation energy reduction and upgrading the quality of the product. This win-win pyrolysis process is a promising pathway for the co-valorization of the cathode materials of spent LIBs and biomass waste.


Assuntos
Lítio , Pirólise , Alcanos , Biomassa , Celulose , Carvão Vegetal , Eletrodos , Hidrocarbonetos , Íons
9.
J Environ Manage ; 315: 115133, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35489190

RESUMO

Waste cathode (BC) from spent lithium-ion battery (LIB) was preliminarily studied for the catalytic pyrolysis of chitin biomass using thermogravimetric and pyrolysis-gas chromatography/mass spectrometry analysis. Compared with the dry-mixing method (BC1), the wet-impregnation method (BC2) significantly increased the decomposition rate of chitin pyrolysis and decreased the apparent activation energy from 85 kJ/mol to 76 kJ/mol. BC2 had a superior catalytic effect on the conversion of heavy components into light fractions. In particular, the selectivities for acetamides and acetonitrile were improved. Furthermore, BC2 enhanced the cleavage of glucosidic, C-O, and C-C bonds, thereby improving the thermolysis of chitin to acetamido acetaldehyde. The production of acetamides, acetonitriles, and other light components (e.g., ketones) was further enhanced via deoxygenation and hydrogenation reactions. Additionally, the selectivity of N-heterocycles (pyridine and pyrrole) and their derivatives (tar-N surrogates) decreased, indicating that tar was significantly reduced during the catalytic pyrolysis and gasification of chitin biomass.


Assuntos
Lítio , Pirólise , Acetamidas , Biomassa , Quitina , Eletrodos , Íons , Termogravimetria , Resíduos
10.
Ying Yong Sheng Tai Xue Bao ; 33(1): 42-50, 2022 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-35224924

RESUMO

We examined the effects of nitrogen addition (0, 30, 60, and 90 kg N·hm-2·a-1) to soil microbial biomass, enzyme activities, and nutrient contents of the Pinus massoniana-Quercus variabilis mixed plantations in the Three Gorges Reservoir Area, with the aim to provide a theoretical basis for predicting soil carbon dynamics under the background of continuously increasing atmospheric nitrogen deposition in this area. The results showed that nitrogen addition at all levels led to a significant increase of the contents of organic carbon, total nitrogen, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial biomass phosphorus (MBP) in the forest soil, while a decrease of soil pH-value, and no significant effect on the total phosphorus content. Nitrogen addition increased the activities of ß-1-4 glucosidase (BG), cellobiose hydrolase (CB), acid phosphatase (AP), N-acetylglucosaminosidase (NAG) and peroxidase (POD), while inhibited that of polyphenol oxidase (PPO). There was a significant seasonal variation in soil oxidase activities, in which the peroxidase activity was higher in May and August, and the polyphenol oxidase activity was the highest in August. Soil enzyme activities were significantly correlated with soil moisture and the contents of soil nutrients, MBC, MBN, and MBP. The variation of soil enzyme activities was caused by the comprehensive effects of multiple factors. The redundancy analysis (RDA) showed that the contents of total soil nitrogen and MBC were the main environmental factors driving soil enzyme activities. The continuous increase of atmosphere nitrogen deposition would lead to soil acidification and promote the turnover of soil organic carbon and nutrient cycling in the Pinus massoniana-Quercus variabilis mixed plantations of the study area.


Assuntos
Pinus , Quercus , Biomassa , Carbono/análise , China , Nitrogênio/análise , Solo , Microbiologia do Solo
11.
J Environ Manage ; 306: 114460, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35026715

RESUMO

Fenton process is the most popular for wastewater treatment among all available advanced oxidation processes (AOPs). Numerous endeavors have been devoted to improving the oxidation efficiency of Fenton reaction in terms of promoting ·OH generation, accelerating iron redox cycle and extending applicable pH range. However, in addition to oxidation, coagulation and adsorption also simultaneously occur in the Fenton process, which play important role in the removal of pollutants. Rapid progress has revealed the synergistic effects of oxidation, coagulation and adsorption in the Fenton process, providing new ideas for the treatment of complex and refractory wastewater. Based on available studies, this review is the first to systematically summarize the research progress regarding the synergistic effects of oxidation, coagulation and adsorption in the integrated Fenton-based processes for wastewater treatment. The involved mechanism of the synergistic effects in different Fenton processes (homogeneous Fenton, heterogeneous Fenton and physical field-assistant Fenton coupling process) are critically reviewed. Furthermore, special attention has been paid to the representative applications of the synergistic effects in wastewater treatment (such as industrial organic wastewater, landfill leachate and heavy metal-organic complexes, etc.), particularly focusing on the operation parameters and removal performance. Finally, a conclusion of the review and subsequently, perspectives are given for possible research directions. We believe this review can provide useful information for researchers and end-users involved in the development and application of the Fenton process in wastewater treatment.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Adsorção , Peróxido de Hidrogênio , Oxirredução , Eliminação de Resíduos Líquidos
12.
J Fungi (Basel) ; 9(1)2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36675886

RESUMO

Analyzing the molecular and physiological processes that govern the uptake and transport of nitrogen (N) in plants is central to efforts to fully understand the optimization of plant N use and the changes in the N-use efficiency in relation to changes in atmospheric N deposition changes. Here, a field experiment was conducted using the ectomycorrhizal fungi (EMF), Pisolithus tinctorius (Pt) and Suillus grevillei (Sg). The effects of N deposition were investigated using concentrations of 0 kg·N·hm-2a-1 (N0), a normal N deposition of 30 kg·N·hm-2a-1 (N30), a moderate N deposition of 60 kg·N·hm-2a-1 (N60), and a severe N deposition of 90 kg·N·hm-2a-1 (N90), with the goal of examining how these factors impacted root activity, root absorbing area, NH4+ and NO3- uptake kinetics, and the expression of ammonium and nitrate transporter genes in Pinus massoniana seedlings under different levels of N deposition. These data revealed that EMF inoculation led to increased root dry weight, activity, and absorbing area. The NH4+ and NO3- uptake kinetics in seedlings conformed to the Michaelis-Menten equation, and uptake rates declined with increasing levels of N addition, with NH4+ uptake rates remaining higher than NO3- uptake rates for all tested concentrations. EMF inoculation was associated with higher Vmax values than were observed for non-mycorrhizal plants. Nitrogen addition resulted in the upregulation of genes in the AMT1 family and the downregulation of genes in the NRT family. EMF inoculation under the N60 and N90 treatment conditions resulted in the increased expression of each of both these gene families. NH4+ and NO3- uptake kinetics were also positively correlated with associated transporter gene expression in P. massoniana roots. Together, these data offer a theoretical foundation for EMF inoculation under conditions of increased N deposition associated with climate change in an effort to improve N absorption and transport rates through the regulation of key nitrogen transporter genes, thereby enhancing N utilization efficiency and promoting plant growth. Synopsis: EMF could enhance the efficiency of N utilization and promote the growth of Pinus massoniana under conditions of increased N deposition.

13.
Bioresour Technol ; 337: 125476, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34320756

RESUMO

This paper proposed a novel method for modification of dolomite (Do) using the leaching solution derived from the spent ternary LIBs. During catalytic pyrolysis of biomass, the modified Do showed a good performance on both reducing the activation energy and upgrading the volatile products. The apparent activation energy was decreased from 201 to 180 kJ/mol for the cellulose pyrolysis, and it was decreased from 80 to 75 kJ/mol for the lignin pyrolysis. The cellulose pyrolysis with the modified Do could significantly promote the conversion of anhydrosugars into small-molecule components (e.g., ketones). Meanwhile, the Do modified by transition-metal (e.g., Mn, Co, Ni) oxides had a high catalytic activity in cracking phenols (main tar precursors) to hydrocarbons (e.g., aromatics) during the lignin pyrolysis. The modified Do inhibited the production of phenols (from 50% to 5.8%) and enhanced the production of hydrocarbons (from 0.6% to 30.3%).


Assuntos
Lítio , Pirólise , Biomassa , Carbonato de Cálcio , Catálise , Cromatografia Gasosa-Espectrometria de Massas , Magnésio
14.
Sleep Breath ; 25(4): 2073-2081, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33754248

RESUMO

PURPOSE: Snoring is one of the cardinal presentations of obstructive sleep apnea (OSA) and is more common than OSA. Abundant evidence has suggested a robust association between OSA and coronary artery disease (CAD). However, whether or not snoring alone is related to a higher risk of CAD is unknown. This study systematically reviewed observational studies with meta-analysis to evaluate the linkage between snoring and CAD. METHODS AND RESULTS: We searched PubMed and Embase and retrieved 13 articles focusing on the relationship between snoring and CAD. These articles included a total of 151,366 participants and 9099 CAD patients. Quantitative analysis indicated that snoring was associated with a 28% (RR: 1.28, 95% CI: 1.13 to 1.45, P < 0.001) increase in the risk of developing CAD. CONCLUSIONS: Snorers are exposed to a 28% increased risk for CAD. Although the association may be partly mediated through OSA, most snorers are not affected by apnea. Given the high prevalence of snoring and the disease burden of CAD in the general population, screening for snoring may be worthwhile for the early prevention of CAD.


Assuntos
Doença da Artéria Coronariana/etiologia , Estudos Observacionais como Assunto , Apneia Obstrutiva do Sono/complicações , Ronco/complicações , Humanos
15.
Environ Sci Pollut Res Int ; 28(21): 27420-27431, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33511530

RESUMO

Pinus elliottii is an evergreen coniferous tree. It is considered a potential species for ecological restoration in the Three Gorges Reservoir Area (TGRA). To classify the effects of different degrees of flooding stress in winter on nutrient accumulation in Pinus elliottii after experiencing early drought stress in summer, simulated water treatments of deep submergence (DS) and moderate submergence (MS) were imposed after the summer drought period. The results indicated that the survival rate of seedlings was 95.3%, and the accumulation trend of the flooded plants was rapid at an average rate of 1.99 ± 0.33% in the early stage of flooding (stage I: 0-7 days), a rapid release rate in the second stage (stage II: 7-60 days), and an average rate of only 0.07 ± 0.04% in the later stage (stage III: 60-150 days). After 150 days of flooding, the leaves of Pinus elliottii released an average of 7.156 ± 0.4 g kg-1 of organic carbon, 8.839 ± 0.6 g kg-1 of nitrogen, 0.781 ± 0.1 g kg-1 of phosphorus, and 2.985 ± 0.3 g kg-1 of potassium of macroelement content, and an average of 0.201 ± 0.03 g kg-1 manganese, 0.147 ± 0.04 g kg-1 iron, 0.002 g kg-1 copper, and 0.023 g kg-1 of zinc of microelement contents. Our results also demonstrated that after 150 days of flooding, the C/N, N/P, and C/P ratios of the nutrient element content of Pinus elliottii in the water-level fluctuation zone of the TGRA were 0.810%, 11.32%, and 9.16%, respectively. The absorption and release of nutrients under water flooding are generally divided into three stages: first, the early storage stage (the first stage: 0 to 7 days, optional), then the rapid release (the second stage: 7 to 60 days), and the later stage slow release phase (third stage: 60 to 150 days). Water flooding reduced the contents of C, N, P, and K and affected the absorption of nutrient elements in the plant. At the same time, soluble Mn2 + and Fe2 + over absorbed during flooding could cause toxicity to leaf tissues. At the same time, Pinus elliottii selected to reduce Cu in leaves to ensure that the root has a strong redox capacity and improve nitrogen utilization, thereby preventing the long-term flooding of toxic cations and acid substances. Taken together, our results conclude that increased drought stress can reduce the ability of Pinus elliottii seedlings to withstand flooding stress; the seedlings of Pinus elliottii can maintain their growth by accumulating certain nutrient elements under submerged conditions, which implies that this species would be a suitable candidate for reforestation in the TGRA because of its tolerance to submergence.


Assuntos
Pinus , Plântula , Nutrientes , Folhas de Planta , Árvores
16.
Bioresour Technol ; 323: 124584, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33373799

RESUMO

This research work studied the pyrolysis characteristics of main biomass components (i.e. cellulose, lignin) in the presence of the spent Li-ion battery cathode (BC) enriched in transition-metals (e.g., Ni, Co). The BC with a good thermostability even at > 700 °C could be used as a catalyst for biomass conversion. The addition methods of BC to biomass such as one-step (directly mixing) and two-step (impregnation-drying) were comparatively studied. The two-step method had a better catalytic effect in biomass pyrolysis, contributing to the reduction of decomposition temperature and activation energy. Significantly, the two-step method had a strong catalytic effect in reducing the content of cellulose-derived sugars and increasing the content of ketones via dehydration and decarboxylation. In addition, the BC used by the two-step method had a high potential for biomass pyrolysis or gasification in promoting the catalytic cracking (i.e. H-transfer) of lignin-derived phenols (tar surrogates) to hydrocarbons and aliphatics (e.g., ketones).


Assuntos
Lítio , Pirólise , Biomassa , Catálise , Lignina
17.
Environ Res ; 189: 109956, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32980025

RESUMO

This paper reported a sustainable method for preparation of N-doped porous carbon from co-hydrothermal carbonization (co-HTC) of lignocellulose (as a carbon skeleton) and sludge protein (as a nitrogen dopant). The HTC pretreatment could improve the yield of porous carbon. Although a low mass ratio (1:1) of biochar and KOH was employed, large specific surface areas of the porous carbons could be achieved. The porous carbon from rice husk (RH) by the HTC (260 °C) combined with the KOH activation (750 °C) had a largest BET surface area up to 1396.5 m2/g. Meanwhile, its adsorption capacity on toluene could reach 394.2 mg/g. It was attributed to its large specific surface area and hierachical porous structure with higher meso-porosity. The porous carbons with N-doping also improved the adsorption capacity. Furthermore, thermal desorption at around 300 °C had a high potential for regeneration of the saturated porous carbons.


Assuntos
Carbono , Nitrogênio , Lignina , Porosidade , Proteínas
18.
Sci Total Environ ; 743: 140760, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653719

RESUMO

The alkaline-earth-metal (AEM) has a good performance on modification of both bio-oil and biochar during biomass pyrolysis. In this work, the pyrolysis of rice husk (RH) in the presence of CaO, CaCO3, MgO and MgCO3 was comparatively studied for selecting an appropriate AEM additive to balance the qualities of pyrolytic products. Pyrolysis of RH with the AEM additives could decrease the acids content and increase the hydrocarbons content in bio-oil. Compared with the Ca-additives (i.e., CaO, CaCO3), the Mg-additives (i.e., MgO, MgCO3) were more beneficial for enhancing the hydrocarbons production. The addition of biochar to soil can significantly enhance the water retention. RHC-MgCO3 had a maximum water retention capacity, while RHC-MgO had a minimum water retention capacity due to its lowest specific surface area. Additionally, the Mg-modified biochar had a much higher nutrient (i.e., K+, PO43-) adsorption capacity. In particular, RHC-MgO with a lowest specific surface area had a highest PO43- adsorption capacity, which was evidenced by the adsorption of PO43- onto biochar mainly controlled by the chemisorption process. PO43- adsorbed in the RHC-MgO released rapidly indicating its low PO43- retention capacity. In general, MgCO3 would be an appropriate candidate that is used in pyrolysis of biomass for co-production of bio-oil and biochar composite with high capacities of water/nutrient adsorption and retention for soil amendment.


Assuntos
Pirólise , Solo , Adsorção , Biomassa , Carvão Vegetal , Metais , Óleos de Plantas , Polifenóis
19.
Bioresour Technol ; 293: 122076, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31479853

RESUMO

This work comparatively studied the catalytic effect of MgO and MgCO3 on pyrolysis of rice husk (RH). The apparent activation energy (E) was reduced significantly by pyrolysis of RH with MgCO3, thus lowering the decomposition temperature during pyrolysis. MgO could not obviously influence the gas evolution during pyrolysis, while MgCO3 had a better performance on the syngas (H2 and CO) generation at around 600-700 °C. Also, the generation of CO2 was suppressed by the RH pyrolysis with MgCO3. The phenols were the dominant compounds in the bio-oil derived from RH. Furthermore, co-pyrolysis of RH and polyvinyl chloride (PVC) in the presence of MgO or MgCO3 at 600 °C could improve the oils quality by decreasing the acids content and increasing the hydrocarbons content. Particularly, the resulting oils had high hydrocarbons content (>35%) and low acids content (<2%). The decrease of acids, alcohols, and phenols contributed to the increase of hydrocarbons.


Assuntos
Óxido de Magnésio , Pirólise , Biocombustíveis , Biomassa , Plásticos
20.
Waste Manag ; 87: 86-96, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31109588

RESUMO

The pyrolysis and combustion kinetics of biomass pellets (i.e., rice husk, herb residue, and wood residue) with the calcium-rich wastes (i.e., CaO, CaCO3, and eggshell) from agro-forestry residues were comparatively studied. During pyrolysis or combustion of biomass, the Ca-rich wastes could slightly influence the decomposition rate in the stage of devolatilization at relatively lower temperatures (e.g., <400 °C). However, the lignin decomposition and the char combustion were obviously influenced by the calcium-based catalysis at higher temperatures (>700 °C). Particularly, the eggshell had a lowest activation energy in the stage of char combustion. The presence of alkali and alkaline-earth metals (AAEMs) in the eggshells might have positive effects on volatile and char combustion. During the combustion, the decomposition temperatures of CaCO3 and eggshell were decreased, thereby favoring to uptake CO2. Furthermore, by identifying the small molecular products, it was found that both CaCO3 and CaO can improve the pyrolysis of RH, but CaCO3 showed better performances, especially on CO2 capture at lower temperatures and on the enhancement of CO production.


Assuntos
Cálcio , Agricultura Florestal , Biomassa , Cinética , Lignina , Pirólise
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