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1.
Sci Justice ; 64(2): 193-201, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38431376

RESUMO

Isotopic analysis of human tooth enamel can provide life history information useful in forensic identification. These applications depend on the availability of reference data documenting isotopic values for individuals with known life history and on the comparability of data from reference and case work samples. Here we build on previous methodological research, which has largely focused on paleontological and archaeological samples, and conduct experiments using enamel from modern human teeth targeting three sample preparation variables (sample particle size, storage conditions, and chemical pretreatments). Our results suggest that differences in particle size affect the efficiency of sample reactions during pretreatment and analysis, with coarse particles giving reduced loss of enamel carbonate during acid pretreatments but producing slightly higher oxygen isotope values than fine particles during analysis. Data for samples stored in dry and ambient environments following pretreatment were indistinguishable, suggesting no exchange of oxygen between samples and ambient water vapor. Finally, chemical pretreatments with a range of commonly used reactants and conditions showed a pervasive, moderate oxygen isotope shift associated with acetic acid treatment, which may be caused by exchange of enamel hydroxyl groups with reagents or rinse waters. Collectively, the results emphasize the importance of methodological standardization to improve comparability and reduce potential for bias in the forensic application of tooth enamel isotope data.


Assuntos
Carbono , Esmalte Dentário , Humanos , Tamanho da Partícula , Isótopos de Oxigênio/análise , Esmalte Dentário/química , Isótopos de Carbono/análise
2.
Acta Gastroenterol Belg ; 87(1): 28-33, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38431787

RESUMO

The importance to reach the target to be carbon net zero by 2050, as presented by the European Commission in the European Green Deal, cannot be overestimated. In a current endoscopy world, where single use has found its place and techniques are constantly evolving, it will be a challenge to reach these goals. How can we reconcile this evolution to a carbon neutral status by 2050 without compromising patients care, clinical standards and training needs? The European Society of Gastrointestinal Endoscopy (ESGE) together with the European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) recently published a position statement (1) whereas in the UK there is the work from the green endoscopy group (2) in line with the strategy of the British Society of Gastroenterology (BSG) on sustainability (3). In Flanders, a project called "greendeal in duurzame zorg" had its kick off in March 2023 (4) so it is about time that we in Belgium, as gastroenterologists, start with tangible actions to a more sustainable daily practice. We wrote this position statement in cooperation with the Vlaamse Vereniging voor Gastro-Enterologie (VVGE), the Société royale belge de Gastro-entérologie (SRBGE) and the Belgian Society of Gastrointestinal Endoscopy (BSGIE). We will also work together in the coming years to continue to motivate our members to work on these initiatives and to co-opt new projects within the framework of the greendeal.


Assuntos
Endoscopia Gastrointestinal , Gastroenterologia , Humanos , Bélgica , Endoscopia Gastrointestinal/métodos , Carbono
3.
J Oleo Sci ; 73(3): 293-310, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38432994

RESUMO

Medium-chain triacylglycerol (MCT) is a type of triacylglycerol that has six or seven to twelve carbon chains. It consists of three molecules of fatty acids attached to one molecule of glycerol. Drug delivery system (DDS) is defined as a formulation to distribute drugs into the human body. The unique properties of MCTs have garnered interest in using them as excipients in DDS. Even though there are many significant effects attributed to the use of MCTs, especially in modulating the rate of drug delivery in various DDS, they are all limited and intermittent. This warrants a detailed summary of the previous studies on the use of MCTs in various DDS. Therefore, this review focuses on presenting a systematic review of previous studies on the use of MCTs in the last six years and explores the types and effects of MCTs on DDS that employ various types of delivery routes. A systematic search through PubMed, Science Direct and Scopus was performed. Keywords like "medium-chain triglycerides", "medium-chain fatty acids", "medium-chain triglycerides and their fractions", "medium-chain fatty acids and their fractions", "MCTs", "MCFA", "in drug delivery", "in drug delivery system" and their combinations were used. The synonyms of the words were also used to extend the search. A total of 17 articles that met the inclusion criteria were identified. Findings from this review have identified the several MCTs and their fractions used in DDS that employed the oral/enteral, topical, transdermal, parenteral, and pulmonary routes of drug delivery. The review also highlights that the usage of MCTs in DDS results in a better transportation of drugs into the human body.


Assuntos
Carbono , Sistemas de Liberação de Medicamentos , Humanos , Excipientes , Ácidos Graxos , Triglicerídeos
4.
Glob Chang Biol ; 30(3): e17203, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38433341

RESUMO

Microbes affect the global carbon cycle that influences climate change and are in turn influenced by environmental change. Here, we use data from a long-term whole-ecosystem warming experiment at a boreal peatland to answer how temperature and CO2 jointly influence communities of abundant, diverse, yet poorly understood, non-fungi microbial Eukaryotes (protists). These microbes influence ecosystem function directly through photosynthesis and respiration, and indirectly, through predation on decomposers (bacteria and fungi). Using a combination of high-throughput fluid imaging and 18S amplicon sequencing, we report large climate-induced, community-wide shifts in the community functional composition of these microbes (size, shape, and metabolism) that could alter overall function in peatlands. Importantly, we demonstrate a taxonomic convergence but a functional divergence in response to warming and elevated CO2 with most environmental responses being contingent on organismal size: warming effects on functional composition are reversed by elevated CO2 and amplified in larger microbes but not smaller ones. These findings show how the interactive effects of warming and rising CO2 levels could alter the structure and function of peatland microbial food webs-a fragile ecosystem that stores upwards of 25% of all terrestrial carbon and is increasingly threatened by human exploitation.


Assuntos
Dióxido de Carbono , Ecossistema , Humanos , Temperatura , Eucariotos , Carbono
5.
Can Vet J ; 65(3): 213-219, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38434165

RESUMO

A 9-year-old male Labrador retriever dog was presented with dysphagia and presence of hairs on the tongue. Buccal examination revealed ulcerative glossitis and lingual hairs along the midline. Ultrasound and magnetic resonance imaging of the tongue showed multiple hair shafts contained in a proliferative tissue along the midline and extending in a fistulous tract towards the right ventral aspect of the tongue at mid-length. Surgical excision was completed using a carbon-dioxide laser. Histopathological examination revealed a pyogranulomatous inflammation centered on growing hairs, confirming the diagnosis of glossitis and lingual hair heterotopia. At 10 mo after surgery, all clinical signs and glossitis had disappeared despite partial recurrence of hair on the dorsal sulcus and in the sublingual fistula. Key clinical message: Although lingual hair heterotopia usually has no clinical repercussions, associated ulcerative lesions should support imaging and biopsy.Resection of the lesion using a carbon-dioxide laser resulted in a good outcome in this case, but recurrent hair growth is possible.


Hétérotopie pilaire linguale associée à une glossite pyogranulomateuse chez un chien labrador : traitement chirurgical à l'aide d'un laser au dioxyde de carbone. Un chien Labrador mâle entier de 9 ans est présenté pour une dysphagie et la présence de poils sur la langue. L'examen de la cavité buccale met en évidence une glossite sévère associée à des implantations pilaires. L'échographie et l'imagerie par résonance magnétique de la langue mettent en évidence de multiples poils contenus dans du matériel tissulaire s'étendant le long de la ligne médiane et présentant un trajet fistuleux vers la partie ventrale droite de la langue à mi-longueur de cette dernière. Une exérèse est réalisée à l'aide d'un laser au dioxyde de carbone. L'examen histopathologique de la pièce d'exérèse révèle une inflammation pyogranulomateuse centrée sur des poils en croissance, confirmant le diagnostic de glossite et d'hétérotopie pilaire linguale. Dix mois après la chirurgie, aucun signe clinique n'est réapparu et la glossite a disparu, malgré la récidive partielle de poils sur la partie dorsale de la langue et en région sublinguale droite.Message clinique clé : Bien que l'hétérotopie pilaire linguale n'ait généralement pas de répercussion clinique, les lésions ulcéreuses associées devraient justifier une imagerie et une biopsie.La résection de la lésion à l'aide d'un laser au dioxyde de carbone a donné de bons résultats dans ce cas, mais une pousse récurrente des poils est possible.(Traduit par les auteurs).


Assuntos
Doenças do Cão , Glossite , Animais , Masculino , Cães , Glossite/veterinária , Língua , Cabelo , Carbono , Lasers , Doenças do Cão/cirurgia
6.
Int J Nanomedicine ; 19: 1985-2004, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38435754

RESUMO

Introduction: The anti-cancer potency of copper-doped carbon quantum dots (Cu-CDs) against breast cancer progression needs more detailed investigations. Methods: With urea and ethylene glycol applied as carbon sources and copper sulfate used as a reactive dopant, Cu-CDs were synthesized in the current study by a one-step hydrothermal synthesis method, followed by the characterization and biocompatibility evaluations of Cu-CDs. Subsequently, the anti-cancer potency of Cu-CDs against breast cancer progression was confirmed by these biochemical, molecular, and transcriptomic assessments, including viability, proliferation, migration, invasion, adhesion, clonogenicity, cell cycle distribution, apoptosis, redox homeostasis, and transcriptomic assays of MDA-MB-231 cells. Results: The biocompatibility of Cu-CDs was confirmed based on the non-significant changes in the pathological and physiological parameters in the Cu-CDs treated mice, as well as the noncytotoxic effect of Cu-CDs on normal cells. Moreover, the Cu-CDs treatments not only decreased the viability, proliferation, migration, invasion, adhesion, and clonogenicity of MDA-MB-231 cells but also induced the redox imbalance, cell cycle arrest, and apoptosis of MDA-MB-231 cells via ameliorating the mitochondrial dysfunctions and regulating the MAPK signaling pathway. Conclusion: Our findings confirmed the biosafety and excellent anti-cancer potency of Cu-CDs against breast cancer progression by tapping into mechanisms that disrupt malignant behaviors and oxidative homeostasis of breast cancer cells.


Assuntos
Neoplasias , Pontos Quânticos , Animais , Camundongos , Cobre/farmacologia , Apoptose , Carbono/farmacologia
7.
Glob Chang Biol ; 30(3): e17213, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38436125

RESUMO

Paddy fields serve as significant reservoirs of soil organic carbon (SOC) and their potential for terrestrial carbon (C) sequestration is closely associated with changes in SOC pools. However, there has been a dearth of comprehensive studies quantifying changes in SOC pools following extended periods of rice cultivation across a broad geographical scale. Using 104 rice paddy sampling sites that have been in continuous cultivation since the 1980s across China, we studied the changes in topsoil (0-20 cm) labile organic C (LOC I), semi-labile organic C (LOC II), recalcitrant organic C (ROC), and total SOC. We found a substantial increase in both the content (48%) and density (39%) of total SOC within China's paddy fields between the 1980s to the 2010s. Intriguingly, the rate of increase in content and density of ROC exceeded that of LOC (I and II). Using a structural equation model, we revealed that changes in the content and density of total SOC were mainly driven by corresponding shifts in ROC, which are influenced both directly and indirectly by climatic and soil physicochemical factors; in particular temperature, precipitation, phosphorous (P) and clay content. We also showed that the δ13 CLOC were greater than δ13 CROC , independent of the rice cropping region, and that there was a significant positive correlation between δ13 CSOC and δ13 Cstraw . The δ13 CLOC and δ13 CSOC showed significantly negative correlation with soil total Si, suggesting that soil Si plays a part in the allocation of C into different SOC pools, and its turnover or stabilization. Our study underscores that the global C sequestration of the paddy fields mainly stems from the substantial increase in ROC pool.


Assuntos
Oryza , Solo , Carbono , China , Geografia
8.
Extremophiles ; 28(2): 19, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38427139

RESUMO

Organic and inorganic cyanides are widely distributed in nature, yet not much is known about the ability of microorganisms to use these compounds as a source of nitrogen and/or carbon at high temperatures (>80 °C). Here we studied the capacity of organic and inorganic cyanides to support growth of an hyperthermophilic Pyrococcus strain isolated from Deception Island, Antarctica. This microorganism was capable of growing with aromatic nitriles, aliphatic nitriles, heterocyclic nitriles, amino aromatic nitriles and inorganic cyanides as nitrogen and/or carbon source. This is the first report of an hyperthermophilic microorganism able to incorporate these compounds in its nitrogen and carbon metabolism. Based on enzymatic activity and genomic information, it is possibly that cells of this Pyrococcus strain growing with nitriles or cyanide, might use the carboxylic acid and/or the ammonia generated through the nitrilase enzymatic activity, as a carbon and/or nitrogen source respectively. This work expands the temperature range at which microorganisms can use organic and inorganic cyanides to growth, having important implications to understand microbial metabolisms that can support life on Earth and the possibility to support life elsewhere.


Assuntos
Cianetos , Pyrococcus , Cianetos/metabolismo , Regiões Antárticas , Nitrilas , Carbono , Nitrogênio
9.
Nat Commun ; 15(1): 1911, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429292

RESUMO

When the supply of inorganic carbon is limiting, photosynthetic cyanobacteria excrete nitrite, a toxic intermediate in the ammonia assimilation pathway from nitrate. It has been hypothesized that the excreted nitrite represents excess nitrogen that cannot be further assimilated due to the missing carbon, but the underlying molecular mechanisms are unclear. Here, we identified a protein that interacts with nitrite reductase, regulates nitrogen metabolism and promotes nitrite excretion. The protein, which we named NirP1, is encoded by an unannotated gene that is upregulated under low carbon conditions and controlled by transcription factor NtcA, a central regulator of nitrogen homeostasis. Ectopic overexpression of nirP1 in Synechocystis sp. PCC 6803 resulted in a chlorotic phenotype, delayed growth, severe changes in amino acid pools, and nitrite excretion. Coimmunoprecipitation experiments indicated that NirP1 interacts with nitrite reductase, a central enzyme in the assimilation of ammonia from nitrate/nitrite. Our results reveal that NirP1 is widely conserved in cyanobacteria and plays a crucial role in the coordination of C/N primary metabolism by targeting nitrite reductase.


Assuntos
Nitritos , Synechocystis , Nitritos/metabolismo , Nitratos/metabolismo , Nitrito Redutases/genética , Nitrito Redutases/metabolismo , Amônia/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Synechocystis/genética , Synechocystis/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo , Nitrato Redutase/genética , Nitrato Redutase/metabolismo
10.
J Nanobiotechnology ; 22(1): 100, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38462597

RESUMO

BACKGROUND: Despite the higher sensitivity of melanoma towards ferroptosis and photodynamic therapy (PDT), the lack of efficient ferroptosis inducers and the poor solubility of photosensitizers restrict their synergistic strategies. With unique advantages, carbon dots (CDs) are expected to serve as innovative building blocks for combination therapy of cancers. RESULTS: Herein, an ferroptosis/PDT integrated nanoplatform for melanoma therapy is constructed based on chlorin e6-modified Fe ions-doped carbon dots (Fe-CDs@Ce6). As a novel type of iron-carbon hybrid nanoparticles, the as-prepared Fe-CDs can selectively activate ferroptosis, prevent angiogenesis and inhibit the migration of mouse skin melanoma cells (B16), but have no toxicity to normal cells. The nano-conjugated structures facilitate not only the aqueous dispersibility of Ce6, but also the self-accumulation ability of Fe-CDs@Ce6 within melanoma area without requiring extra targets. Moreover, the therapeutic effects of Fe-CDs@Ce6 are synergistically enhanced due to the increased GSH depletion by PDT and the elevated singlet oxygen (1O2) production efficiency by Fe-CDs. When combined with laser irradiation, the tumor growth can be significantly suppressed by Fe-CDs@Ce6 through cyclic administration. The T2-weighted magnetic resonance imaging (MRI) capability of Fe-CDs@Ce6 also reveals their potentials for cancer diagnosis and navigation therapy. CONCLUSIONS: Our findings indicate the multifunctionality of Fe-CDs@Ce6 in effectively combining ferroptosis/PDT therapy, tumor targeting and MRI imaging, which enables Fe-CDs@Ce6 to become promising biocompatible nanoplatform for the treatment of melanoma.


Assuntos
Ferroptose , Melanoma , Nanopartículas , Fotoquimioterapia , Camundongos , Animais , Fotoquimioterapia/métodos , Melanoma/tratamento farmacológico , Carbono/farmacologia , Carbono/química , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/química , Imageamento por Ressonância Magnética , Nanopartículas/química
11.
Environ Monit Assess ; 196(4): 355, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38466496

RESUMO

Vermicompost is a substantial source of nutrients, promotes soil fertility, and maintains or increases soil organic matter levels. Potentially toxic elements (PTEs) in vermicompost impact on nitrification activity. However, it is yet unknown how vermicompost affects nitrifying bacteria and archaea, comammox Nitrospira inopinata (complete ammonia oxidizers), net nitrification rates (NNRs), and PTEs. The effects of vermicompost application on NNRs, potential nitrification rates (NPs), PTEs, and the abundances of comammox N. inopinata bacteria, nitrite-oxidizing bacteria (NOB), and ammonia-oxidizing bacteria (AOB)/archaea (AOA) were studied. NNRs and NPs were significantly higher (p < 0.05) in fresh cow-dung vermicompost (stored for 40 days) as compared with other organic manure. The level of PTEs (Cu2+, Fe2+, Pb2+, Cd2+, and Zn2+) was significantly lower (p < 0.05) in vermicompost as compared with compost of waste material with Trichoderma and cow dung. Comammox N. inopinata, NOB, AOB, and AOA were significantly higher (p < 0.05) in stored cow-dung vermicompost (more than 1 year) as compared with other organic manure. The results of the scatterplot matrix analysis suggested that Fe2+, total nitrogen (TN), soil organic carbon (SOC), and total carbon (TC) were linearly correlated (p < 0.001) with NNRs and NPs in vermicompost and organic manure. Similarly, comammox N. inopinata bacteria, NOB, AOB, and AOA were linearly correlated (p < 0.001) with NNR and NP. These results indicated that vermicompost promoted nitrification activity by increasing microbial diversity and abundance, supplying nutrients and organic matter for microbial growth, and facilitating complex microbial interactions. It may be concluded that the influence of vermicompost, which played a great role in PTE concentration reduction, increased chemical, and biological properties, increased the growth rate of nitrifying bacteria/archaea and the nitrogen cycle.


Assuntos
Archaea , Nitrificação , Esterco , Amônia , Carbono , Oxirredução , Solo/química , Filogenia , Microbiologia do Solo , Monitoramento Ambiental , Bactérias , Nitritos
12.
Mikrochim Acta ; 191(4): 192, 2024 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-38467931

RESUMO

FeOx-TiO2@Carbon hybrid structure materials (FeOx-TiO2@CHs) with high peroxidase (POD)-like activity have been prepared by one-pot hydrothermal method. Based on the excellent POD activity of FeOx-TiO2@CHs, one pot colorimetric detection for glucose was constructed by using TMB as substrate with the synergistic reaction of glucose oxidase; the linear range and the limit of detection (LOD) are 25 ~ 1000 and 1.77 µM, respectively. Using this method, the glucose in serum real samples was detected with satisfactory results, and the results are consistent with that of the glucometer method in the hospital. The recovery in diabetic and artificial urine samples was 95.71 ~ 104.67% and 99.01 ~ 103.16%, respectively. The mechanism of the catalytic colorimetric reaction was also investigated by multiple measurements, and the results indicated that superoxide anions (O2•-) between FeOx-TiO2@CHs and substrate play a main role, but a small quantity of hydroxyl radical •OH and singlet oxygen 1O2 is also generated simultaneously. The one-pot reaction method is simple and fast; the detection process only requires a simple mixing, which is suitable for application in special environment.


Assuntos
Glucose , Peroxidase , Peroxidase/química , Carbono/química , Colorimetria/métodos , Peróxido de Hidrogênio/química , Peroxidases/química , Corantes
13.
Glob Chang Biol ; 30(3): e17233, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38469991

RESUMO

Nitrous oxide (N2 O) exacerbates the greenhouse effect and thus global warming. Agricultural management practices, especially the use of nitrogen (N) fertilizers and irrigation, increase soil N2 O emissions. As a vital sector of global agriculture, specialty crop systems usually require intensive input and management. However, soil N2 O emissions from global specialty crop systems have not been comprehensively evaluated. Here, we synthesized 1137 observations from 114 published studies, conducted a meta-analysis to evaluate the effects of agricultural management and environmental factors on soil N2 O emissions, and estimated global soil N2 O emissions from specialty crop systems. The estimated global N2 O emission from specialty crop soils was 1.5 Tg N2 O-N year-1 , ranging from 0.5 to 4.5 Tg N2 O-N year-1 . Globally, soil N2 O emissions exponentially increased with N fertilizer rates. The effect size of N fertilizer on soil N2 O emissions generally increased with mean annual temperature, mean annual precipitation, and soil organic carbon concentration but decreased with soil pH. Global climate change will further intensify the effect of N fertilizer on soil N2 O emissions. Drip irrigation, fertigation, and reduced tillage can be used as essential strategies to reduce soil N2 O emissions and increase crop yields. Deficit irrigation and non-legume cover crop can reduce soil N2 O emissions but may also lower crop yields. Biochar may have a relatively limited effect on reducing soil N2 O emissions but be effective in increasing crop yields. Our study points toward effective management strategies that have substantial potential for reducing N2 O emissions from global agricultural soils.


Assuntos
Fertilizantes , Solo , Fertilizantes/análise , Carbono , Agricultura , Óxido Nitroso/análise , Nitrogênio/análise
14.
Glob Chang Biol ; 30(3): e17234, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38469998

RESUMO

Rapid biodiversity losses under global climate change threaten forest ecosystem functions. However, our understanding of the patterns and drivers of multiple ecosystem functions across biodiversity gradients remains equivocal. To address this important knowledge gap, we measured simultaneous responses of multiple ecosystem functions (nutrient cycling, soil carbon stocks, organic matter decomposition, plant productivity) to a tree species richness gradient of 1, 4, 8, 16, and 32 species in a young subtropical forest. We found that tree species richness had negligible effects on nutrient cycling, organic matter decomposition, and plant productivity, but soil carbon stocks and ecosystem multifunctionality significantly increased with tree species richness. Linear mixed-effect models showed that soil organisms, particularly arbuscular mycorrhizal fungi (AMF) and soil nematodes, elicited the greatest relative effects on ecosystem multifunctionality. Structural equation models revealed indirect effects of tree species richness on ecosystem multifunctionality mediated by trophic interactions in soil micro-food webs. Specifically, we found a significant negative effect of gram-positive bacteria on soil nematode abundance (a top-down effect), and a significant positive effect of AMF biomass on soil nematode abundance (a bottom-up effect). Overall, our study emphasizes the significance of a multitrophic perspective in elucidating biodiversity-multifunctionality relationships and highlights the conservation of functioning soil micro-food webs to maintain multiple ecosystem functions.


Assuntos
Ecossistema , Micorrizas , Cadeia Alimentar , Árvores , Solo/química , Biodiversidade , Plantas , Carbono
15.
Huan Jing Ke Xue ; 45(3): 1254-1264, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471842

RESUMO

This study explored the carbon metabolism efficiency of a production-living-ecological space system, which is of great significance for regional factor integration and spatial optimization. In this study, the material flow analysis method was introduced to establish a framework for evaluating the carbon metabolism efficiency of the production-living-ecological space system, and the super-efficiency DEA model and Malmquist index were used to empirically analyze the spatio-temporal distribution, dynamic change, and evolution patterns of the carbon metabolism efficiency of production-living-ecological space in the Beijing-Tianjin-Hebei Region, China, from 2000 to 2020 on the basis of the urban metabolic perspective. The results showed that:① the carbon metabolism efficiency of the production-living-ecological space showed a fluctuating growth trend, indicating the significant spatial differentiation of carbon metabolism efficiency in each city. There was a low overall carbon metabolism efficiency level, with a distribution pattern of being high in the middle and low in the north and south. ② The Malmquist index showed that the Total Factor Productivity (TFP) of carbon metabolism efficiency was greater than 1, and both the Technical Change (TC) and Pure Efficiency Change (PEC) were less than 1, in which the TFP showed an increasing trend, whereas there was no significant contribution of technological progress or pure technical efficiency to carbon metabolism efficiency. The total factor productivity of more than 50% of the cities showed an improving trend, only 38.46% of which made technological progress in improving carbon metabolism efficiency, and more than half of the urban pure technical efficiency showed a decreasing trend, in which the technical efficiency change and scale efficiency change were greater than 1 in most cities. ③ There were different types of carbon efficiency characteristics in each city, and according to the movement rules of the corresponding points in the quartile map, the evolution patterns of tourism industry efficiency were classified into stable, reciprocating, progressive, and abrupt. Therefore, local governments should adopt differentiated strategies to reasonably allocate spatial resources of production-living-ecological space and improve the technical level and scale efficiency, so as to improve the efficiency of urban carbon metabolism.


Assuntos
Carbono , Ecossistema , Pequim , Carbono/análise , China , Cidades , Eficiência , Desenvolvimento Econômico
16.
Huan Jing Ke Xue ; 45(3): 1665-1673, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471878

RESUMO

Changes in soil nitrogen components in tea gardens affect the soil nitrogen supply capacity and nitrogen cycle. In this study, soil samples were collected from forest land, cultivated land, and tea gardens with different plantation ages (30, 50, and 70 years) to explore the changes in soil nitrogen components and their relationship with physicochemical properties and enzyme activities. The results showed that:① with the increase in tea plantation age, the silt, total phosphorus, and urease and catalase activities gradually increased, whereas the sand, clay, pH, electrical conductivity, soil organic carbon, and the activities of invertase gradually decreased. The alkaline phosphatase activity increased first and then decreased with the increase in tea plantation age, and no significant differences were observed in soil water content and acid phosphatase activity. ② With the increase in tea plantation age, the contents of acid ammonia nitrogen, amino acid nitrogen, and nitrate nitrogen (NO3--N) increased significantly, and the contents of total nitrogen, acid ammonia nitrogen, hydrolyzable unknown nitrogen, and non-hydrolyzable nitrogen in tea gardens were significantly higher than those in forest land. ③ The total phosphorus, alkaline phosphatase, and urease were the main factors affecting soil nitrogen components. Among them, organic nitrogen components were significantly correlated with total phosphorus and alkaline phosphatase, and inorganic nitrogen components were significantly correlated with alkaline phosphatase, whereas total nitrogen had significant correlations with sand, silt, total phosphorus, urease, and alkaline phosphatase.


Assuntos
Fosfatase Alcalina , Solo , Solo/química , Areia , Nitrogênio/análise , Carbono , Urease , Amônia , Fósforo/análise , Chá , Microbiologia do Solo , China
17.
Physiol Plant ; 176(2): e14235, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38472162

RESUMO

N2 -fixing legumes can strongly affect ecosystem functions by supplying nitrogen (N) and improving the carbon-fixing capacity of vegetation. Still, the question of how their leaf-level N status and carbon metabolism are coordinated along leaf ageing remains unexplored. Leaf tissue carbon isotopic composition (δ13 C) provides a useful indicator of time-integrated intrinsic water use efficiency (WUEi). Here, we quantified the seasonal changes of leaf δ13 C, N content on a mass and area basis (Nmass , Narea , respectively), Δ18 O (leaf 18 O enrichment above source water, a proxy of time-integrated stomatal conductance) and morphological traits in an emblematic N2 -fixing legume tree, the black locust (Robinia pseudoacacia L.), at a subtropical site in Southwest China. We also measured xylem, soil and rainwater isotopes (δ18 O, δ2 H) to characterize tree water uptake patterns. Xylem water isotopic data reveal that black locust primarily used shallow soil water in this humid habitat. Black locust exhibited a decreasing δ13 C along leaf ageing, which was largely driven by decreasing leaf Nmass , despite roughly constant Narea . In contrast, the decreasing δ13 C along leaf ageing was largely uncoupled from parallel increases in Δ18 O and leaf thickness. Leaf N content is used as a proxy of leaf photosynthetic capacity; thus, it plays a key role in determining the seasonality in δ13 C, whereas the roles of stomatal conductance and leaf morphology are minor. Black locust leaves can effectively adjust to changing environmental conditions along leaf ageing through LMA increases and moderate stomatal conductance reduction while maintaining constant Narea to optimize photosynthesis and carbon assimilation, despite declining leaf Nmass and δ13 C.


Assuntos
Fabaceae , Robinia , Árvores/metabolismo , Ecossistema , Fabaceae/metabolismo , Folhas de Planta/metabolismo , Carbono/metabolismo , Solo , Água/metabolismo , Nitrogênio/metabolismo
18.
Environ Monit Assess ; 196(4): 360, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472494

RESUMO

As a crucial ecological protection area in China, the Southern hilly red soil region is characterized by uneven spatial and temporal distribution of ecological landscape elements, unpredictable and changeable interrelationships between them, diversified driving factors, and lack of comprehensive consideration of ecosystem services. In order to better understand the interaction between ecosystem services, restore regional ecology, and promote sustainable development, the evolution law and influencing mechanism of ecosystem services and their driving factors are quantitatively analyzed in the study. Based on simulations of different ecosystem services from 2000 to 2020, their spatial and temporal changes and the contributions of main drivers are quantified, their trade-offs and synergies are analyzed, and the changing rules under the influence of natural factors and socioeconomic factors are explored. The results show that (1) the crop production significantly increases in the southwest and north regions, the habitat quality decreases in urban and coastal areas, and the soil retention and water yield show an increasing trend from west to east. (2) Land use/cover is the main driver of carbon storage and habitat quality variation, and precipitation is an important driver of water yield spatial variation. (3) The crop production and the other four ecosystem services show a trade-offs relationship, and the relationship between supporting services and regulating services is the synergetic. (4) The altitude weakens the synergistic relationship between soil retention and habitat quality/carbon storage, while it enhances the synergistic relationship between soil retention and water yield. Driven by precipitation factors, ecosystem services related to water yield have significant differences in the change. The population density enhances the trade-offs of crop production and soil retention, as well as the synergistic relationship between soil retention and habitat quality/carbon storage. In different land use/cover (LULC), the influence of urban land on ecosystem services relationship change is more obvious. Overall, this study can provide scientific bases and policy suggestions for ecosystem protection/restoration in the red soil region of Southern China, which has an important theoretical and practical significance.


Assuntos
Ecossistema , Solo , Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , China , Carbono , Água
19.
Geobiology ; 22(2): e12593, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476006

RESUMO

Biological processes in the Proterozoic Ocean are often inferred from modern oxygen-deficient environments (MODEs) or from stable isotopes in preserved sediment. To date, few MODE studies have simultaneously quantified carbon fixation genes and attendant stable isotopic signatures. Consequently, how carbon isotope patterns reflect these pathways has not been thoroughly vetted. Addressing this, we profiled planktonic productivity and quantified carbon fixation pathway genes and associated organic carbon isotope values (δ13 CPOC ) of size-fractionated (0.2-2.7 and >2.7 µm) particulate matter from meromictic Fayetteville Green Lake, NY, USA. The high-O2 Calvin-Benson-Bassham (CBB) gene (cbbL) was most abundant in the <2.7 µm size fraction in shallow oxic and deep hypoxic waters, corresponding with cyanobacterial and eukaryote algal populations. The low-O2 CBB gene (cbbM) was most abundant near the lower oxycline boundary in the larger size fraction, coincident with purple sulfur bacteria populations. The reverse citric acid cycle gene (aclB) was equally abundant in both size fractions in the deepest photic zone, coinciding with green sulfur bacteria populations. Methane coenzyme reductase A (mcrA), of anaerobic methane cyclers, was most abundant at the lower oxycline boundary in both size fractions, coinciding with Methanoregula populations. δ13 CPOC values overlapped with the high-O2 CBB fixation range except for two negative excursions near the lower oxycline boundary, likely reflecting assimilation of isotopically-depleted groundwater-derived carbon by autotrophs and sulfate-reducers. Throughout aphotic waters, δ13 CPOC values of the large size fraction became 13 C-enriched, likely reflecting abundant purple sulfur bacterial aggregates. Eukaryote algae- or cyanobacteria-like isotopic signatures corresponded with increases in cbbL, cbbM, and aclB, and enrichment of exopolymer-rich prokaryotic photoautotrophs aggregates. Results suggest that δ13 CPOC values of preserved sediments from areas of the Proterozoic Ocean with sulfidic photic zones may reflect a mixture of alternate carbon-fixing populations exported from the deep photic zone, challenging the paradigm that sedimentary stable carbon isotope values predominantly reflect oxygenic photosynthesis from surface waters.


Assuntos
Chromatiaceae , Cianobactérias , Carbono/metabolismo , Lagos/microbiologia , Isótopos de Carbono/análise , Cianobactérias/metabolismo , Oxigênio/análise , Chromatiaceae/metabolismo , Metano , Oceanos e Mares
20.
Int J Nanomedicine ; 19: 2265-2284, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476273

RESUMO

Introduction: Glaucoma is a prevalent cause of irreversible vision impairment, characterized by progressive retinal ganglion cells (RGCs) loss, with no currently available effective treatment. Rapamycin (RAPA), an autophagy inducer, has been reported to treat glaucoma in rodent models by promoting RGC survival, but its limited water solubility, systemic toxicity, and pre-treatment requirements hinder its potential clinical applications. Methods: Chitosan (CS)-RAPA carbon dot (CRCD) was synthesized via hydrothermal carbonization of CS and RAPA and characterized by transmission electron microscopy, Fourier transform infrared spectra, and proton nuclear magnetic resonance. In vitro assays on human umbilical cord vein endothelial and rat retinal cell line examined its biocompatibility and anti-oxidative capabilities, while lipopolysaccharide-stimulated murine microglia (BV2) assays measured its effects on microglial polarization. In vivo, using a mouse retinal ischemia/reperfusion (I/R) model by acute intraocular pressure elevation, the effects of CRCD on visual function, RGC apoptosis, oxidative stress, and M2 microglial polarization were examined. Results: CRCD exhibited good water solubility and anti-oxidative capabilities, in the form of free radical scavenging. In vitro, CRCD was bio-compatible and lowered oxidative stress, which was also found in vivo in the retinal I/R model. Additionally, both in vitro with lipopolysaccharide-stimulated BV2 cells and in vivo with the I/R model, CRCD was able to promote M2 microglial polarization by activating autophagy, which, in turn, down-regulated pro-inflammatory cytokines, such as IL-1ß and TNF-α, as well as up-regulated anti-inflammatory cytokines, such as IL-4 and TGF-ß. All these anti-oxidative and anti-inflammatory effects ultimately aided in preserving RGCs, and subsequently, improved visual function. Discussion: CRCD could serve as a potential novel treatment strategy for glaucoma, via incorporating RAPA into CDs, in turn not only mitigating its toxic side effects but also enhancing its therapeutic efficacy.


Assuntos
Quitosana , Glaucoma , Traumatismo por Reperfusão , Ratos , Animais , Camundongos , Humanos , Microglia/patologia , Quitosana/farmacologia , Sirolimo/farmacologia , Carbono/farmacologia , Lipopolissacarídeos/farmacologia , Glaucoma/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Modelos Animais de Doenças , Autofagia , Citocinas/metabolismo , Água , Traumatismo por Reperfusão/tratamento farmacológico
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