Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74.530
Filtrar
1.
Environ Monit Assess ; 196(5): 434, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38584211

RESUMO

Forest biomass plays a crucial role in the global carbon cycle as a significant contributor derived from both soil and trees. This study focuses on investigating tree carbon stock (TCS) and estimating aboveground biomass (AGB) based on elevation within the Srivilliputhur Wildlife Sanctuary forest, while also exploring the various factors that influence their contribution. Utilizing a non-destructive approach for carbon estimation, we found that the total tree biomass in this region ranged from 220.9 Mg/ha (in Z6) to 720.6 Mg/ha (Z2), while tree carbon stock ranged from 103.8 to 338.7 Mg/ha. While Kruskal-Wallis tests did not reveal a significant relationship (p = 0.09) between TCS and elevation, linear regression showed a weak correlation (R2 = 0.002, p < 0.05) with elevation. To delve deeper into the factors influencing TCS and biomass distribution, we employed a random forest (RF) machine learning algorithm, demonstrating that stand structural attributes, such as basal area (BA), diameter at breast height (DBH), and density, held a more prominent role than climatic variables, including temperature, precipitation, and slope. Generalized linear models (GLM) were also utilized, confirming that BA, mean DBH, and elevation significantly influenced AGB (p ≤ 0.001), with species richness, precipitation, and temperature having lower significance (p ≤ 0.01) comparatively. Overall, the RF model exhibited superior performance (R2 = 0.92, RMSE = 0.12) in terms of root mean square error (RMSE) compared to GLM (R2 = 0.88, RMSE = 0.35). These findings shed light on the intricate dynamics of biomass distribution and the importance of both stand structural and climatic factors in shaping forest ecosystems.


Assuntos
Animais Selvagens , Ecossistema , Animais , Biomassa , Monitoramento Ambiental , Carbono/análise
2.
Methods Mol Biol ; 2798: 79-100, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38587737

RESUMO

Malondialdehyde is a three-carbon dialdehyde produced as a byproduct of polyunsaturated fatty acid peroxidation widely used as a marker of the extent of lipid peroxidation in plants. There are several methodological approaches to quantify malondialdehyde contents in higher plants, ranging from the simplest, cheapest, and quickest spectrophotometric approaches to the more complex ones using tandem mass spectrometry. This chapter summarizes the advantages and limitations of approaches followed and provides brief protocols with some tips to facilitate the selection of the best method for each experimental condition and application.


Assuntos
Embriófitas , Bioensaio , Carbono , Peroxidação de Lipídeos , Malondialdeído
3.
Environ Monit Assess ; 196(5): 435, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587761

RESUMO

Simple and sensitive electrochemical sensors were fabricated from cerium oxide (CeO2) and copper-benzene tricarboxylic acid-modified cerium oxide (CeO2-Cu-BTC) materials for differential pulse voltammetric analysis of toxic cadmium (Cd) ions in aqueous solutions. The materials were prepared by hydrothermal method and structurally characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray (SEM-EDX), thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). The CeO2-modified carbon paste electrode (CeCPE) and the CeO2-Cu-BTC-modified carbon paste electrode (CeBCPE) were electrochemically characterized by their cyclic voltammetry and electrochemical impedance study in standard K3[Fe(CN)6] single-electron redox process. Their electrochemical surface areas, electrode surface coverages, and charge transfer resistances were calculated to be 1.46 cm2, 2.338 × 10-5 mol∙cm-2, and 2790 Ω and 5.48 cm2, 2.476 × 10-5 mol∙cm-2, and 1254.65 Ω for CeCPE and CeBCPE, respectively. These fabricated electrodes were used as electrochemical sensors for cadmium ion estimation by optimizing the experimental parameters through differential pulse voltammetry. The optimized conditions included 10% modifier for CeCPE and 5% modifier for CeBCPE in 0.12 M HCl solution of pH 5 as supporting electrolyte at - 1.2 V deposition for 30 s in 0.01 to 10 mg L-1 linear cadmium solution range. Under these conditions, the limit of quantification (LOQ) of 0.368 mg L-1 and 0.005 mg L-1 was calculated for CeCPE and CeBCPE electrodes, respectively. The limit of detection (LOD) was calculated to be 0.121 mg L-1 and 0.002 mg L-1 for CeCPE and CeBCPE, respectively. All the experimental results indicated that electrodes fabricated from CeO2-Cu-BTC show better performance as compared to CeO2-based electrodes. Both these types of electrochemical sensors presented good repeatability and performance in the presence of interfering ions as well. From these findings, it can also be inferred that these electrochemical sensors can provide a simple and very sensitive method for approximation of toxic cadmium ions in aqueous solutions.


Assuntos
Cádmio , Cério , Cobre , Cicloexanos , Monitoramento Ambiental , Íons , Carbono
4.
Top Curr Chem (Cham) ; 382(2): 12, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589598

RESUMO

Organoselenium compounds have been the subject of extensive research since the discovery of the biologically active compound ebselen. Ebselen has recently been found to show activity against the main protease of the virus responsible for COVID-19. Other organoselenium compounds are also well-known for their diverse biological activities, with such compounds exhibiting interesting physical properties relevant to the fields of electronics, materials, and polymer chemistry. In addition, the incorporation of selenium into various organic molecules has garnered significant attention due to the potential of selenium to enhance the biological activity of these molecules, particularly in conjunction with bioactive heterocycles. Iodine and iodine-based reagents play a prominent role in the synthesis of organoselenium compounds, being valued for their cost-effectiveness, non-toxicity, and ease of handling. These reagents efficiently selenylate a broad range of organic substrates, encompassing alkenes, alkynes, and cyclic, aromatic, and heterocyclic molecules. They serve as catalysts, additives, inducers, and oxidizing agents, facilitating the introduction of different functional groups at alternate positions in the molecules, thereby allowing for regioselective and stereoselective approaches. Specific iodine reagents and their combinations can be tailored to follow the desired reaction pathways. Here, we present a comprehensive review of the progress in the selenylation of organic molecules using iodine reagents over the past decade, with a focus on reaction patterns, solvent effects, heating, microwave, and ultrasonic conditions. Detailed discussions on mechanistic aspects, such as electrophilic, nucleophilic, radical, electrochemical, and ring expansion reactions via selenylation, multiselenylation, and difunctionalization, are included. The review also highlights the formation of various cyclic, heterocyclic, and heteroarenes resulting from the in situ generation of selenium intermediates, encompassing cyclic ketones, cyclic ethers, cyclic lactones, selenophenes, chromones, pyrazolines, pyrrolidines, piperidines, indolines, oxazolines, isooxazolines, lactones, dihydrofurans, and isoxazolidines. To enhance the reader's interest, the review is structured into different sections covering the selenylation of aliphatic sp2/sp carbon and cyclic sp2 carbon, and then is further subdivided into various heterocyclic molecules.


Assuntos
Iodo , Isoindóis , Compostos Organosselênicos , Selênio , Iodo/química , Indicadores e Reagentes , Compostos Organosselênicos/química , Lactonas/química , Carbono
5.
Environ Monit Assess ; 196(5): 437, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592553

RESUMO

Impervious surface cover increases peak flows and degrades stream health, contributing to a variety of hydrologic, water quality, and ecological symptoms, collectively known as the urban stream syndrome. Strategies to combat the urban stream syndrome often employ engineering approaches to enhance stream-floodplain reconnection, dissipate erosive forces from urban runoff, and enhance contaminant retention, but it is not always clear how effective such practices are or how to monitor for their effectiveness. In this study, we explore applications of longitudinal stream synoptic (LSS) monitoring (an approach where multiple samples are collected along stream flowpaths across both space and time) to narrow this knowledge gap. Specifically, we investigate (1) whether LSS monitoring can be used to detect changes in water chemistry along longitudinal flowpaths in response to stream-floodplain reconnection and (2) what is the scale over which restoration efforts improve stream quality. We present results for four different classes of water quality constituents (carbon, nutrients, salt ions, and metals) across five watersheds with varying degrees of stream-floodplain reconnection. Our work suggests that LSS monitoring can be used to evaluate stream restoration strategies when implemented at meter to kilometer scales. As streams flow through restoration features, concentrations of nutrients, salts, and metals significantly decline (p < 0.05) or remain unchanged. This same pattern is not evident in unrestored streams, where salt ion concentrations (e.g., Na+, Ca2+, K+) significantly increase with increasing impervious cover. When used in concert with statistical approaches like principal component analysis, we find that LSS monitoring reveals changes in entire chemical mixtures (e.g., salts, metals, and nutrients), not just individual water quality constituents. These chemical mixtures are locally responsive to restoration projects, but can be obscured at the watershed scale and overwhelmed during storm events.


Assuntos
Rios , Sais , Qualidade da Água , Monitoramento Ambiental , Carbono , Cloreto de Sódio
6.
Microb Cell Fact ; 23(1): 101, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38566056

RESUMO

BACKGROUND: Short-chain fatty acids (SCFAs) are cost-effective carbon sources for an affordable production of lipids. Hexanoic acid, the acid with the longest carbon chain in the SCFAs pool, is produced in anaerobic fermentation of organic residues and its use is very challenging, even inhibiting oleaginous yeasts growth. RESULTS: In this investigation, an adaptive laboratory evolution (ALE) was performed to improve Yarrowia lipolytica ACA DC 50109 tolerance to high hexanoic acid concentrations. Following ALE, the transcriptomic analysis revealed several genetic adaptations that improved the assimilation of this carbon source in the evolved strain compared to the wild type (WT). Indeed, the evolved strain presented a high expression of the up-regulated gene YALI0 E16016g, which codes for FAT1 and is related to lipid droplets formation and responsible for mobilizing long-chain acids within the cell. Strikingly, acetic acid and other carbohydrate transporters were over-expressed in the WT strain. CONCLUSIONS: A more tolerant yeast strain able to attain higher lipid content under the presence of high concentrations of hexanoic acid has been obtained. Results provided novel information regarding the assimilation of hexanoic acid in yeasts.


Assuntos
Yarrowia , Fermentação , Yarrowia/metabolismo , Caproatos/metabolismo , Ácidos Graxos Voláteis/metabolismo , Ácidos Graxos/metabolismo , Ácidos/metabolismo , Perfilação da Expressão Gênica , Carbono/metabolismo
7.
Microbiome ; 12(1): 68, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570877

RESUMO

BACKGROUND: The trophic strategy is one key principle to categorize microbial lifestyles, by broadly classifying microorganisms based on the combination of their preferred carbon sources, electron sources, and electron sinks. Recently, a novel trophic strategy, i.e., chemoorganoautotrophy-the utilization of organic carbon as energy source but inorganic carbon as sole carbon source-has been specifically proposed for anaerobic methane oxidizing archaea (ANME-1) and Bathyarchaeota subgroup 8 (Bathy-8). RESULTS: To further explore chemoorganoautotrophy, we employed stable isotope probing (SIP) of nucleic acids (rRNA or DNA) using unlabeled organic carbon and 13C-labeled dissolved inorganic carbon (DIC), i.e., inverse stable isotope labeling, in combination with metagenomics. We found that ANME-1 archaea actively incorporated 13C-DIC into RNA in the presence of methane and lepidocrocite when sulfate was absent, but assimilated organic carbon when cellulose was added to incubations without methane additions. Bathy-8 archaea assimilated 13C-DIC when lignin was amended; however, their DNA was derived from both inorganic and organic carbon sources rather than from inorganic carbon alone. Based on SIP results and supported by metagenomics, carbon transfer between catabolic and anabolic branches of metabolism is possible in these archaeal groups, indicating their anabolic versatility. CONCLUSION: We provide evidence for the incorporation of the mixed organic and inorganic carbon by ANME-1 and Bathy-8 archaea in the environment. Video Abstract.


Assuntos
Archaea , Metano , Archaea/genética , Marcação por Isótopo , Oxirredução , Metano/metabolismo , Carbono/metabolismo , DNA , Anaerobiose , Sedimentos Geológicos , Filogenia
8.
Proc Natl Acad Sci U S A ; 121(15): e2318425121, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38557182

RESUMO

Corrugated packaging for express grew by 90 times to 16.5 Mt y-1 in China, where 81% of recent global express delivery growth occurred. However, the environmental impacts of production, usage, disposal, and recycling of corrugated boxes under the entire supply chain remain unclear. Here, we estimate the magnitudes, drivers, and mitigation potentials of cradle-to-grave life-cycle carbon footprint (CF) and three colors of water footprints (WFs) for corrugated cardboard packaging in China. Over 2007 to 2021, CF, blue and gray WFs per unit package decreased by 45%, 60%, and 84%, respectively, while green WF increased by 23% with growing imports of virgin pulp and China's waste ban. National total CF and WFs were 21 to 102 folded with the scale effects. Only a combination of the supply chain reconstruction, lighter single-piece packaging, and increased recycling rate can possibly reduce the environmental footprints by 24 to 44% by 2035.


Assuntos
Carbono , Água , Pegada de Carbono , Reciclagem , China
9.
PLoS One ; 19(4): e0301333, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38557854

RESUMO

The scale of multi-microgrid (MMG) and hydrogen fuel cell vehicles (HFCVs) is increasing dramatically with the increase in the new energy penetration ratio, and developing an integrated energy system containing a multi-microgrid for hydrogen fuel vehicles brings great challenges to power grid operation. Focusing on the difficulties of the access of multiple microgrids for the low-carbon and economic operation of the system, this paper proposes an optimal interconnected heterogeneous multi-microgrid power-heat-carbon scheduling strategy for hydrogen-fueled vehicles. Firstly, an HFCV model is established, and then an optimal scheduling model is constructed for the cooperative trading of power-heat-carbon in a multi-microgrid, on the basis of which the low-carbon economic operation of the multi-microgrid is realized. The results of the case study show that the scheduling strategy in this paper reduces carbon emissions by about 7.12% and costs by about 3.41% compared with the independent operation of the multi-microgrid. The degrees of interaction of each multi-microgrid are also analyzed under different HFCV penetration rates.


Assuntos
Carbono , Hidrogênio , Temperatura Alta , Custos e Análise de Custo
10.
Glob Chang Biol ; 30(4): e17268, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38562029

RESUMO

Although substantial advances in predicting the ecological impacts of global change have been made, predictions of the evolutionary impacts have lagged behind. In soil ecosystems, microbes act as the primary energetic drivers of carbon cycling; however, microbes are also capable of evolving on timescales comparable to rates of global change. Given the importance of soil ecosystems in global carbon cycling, we assess the potential impact of microbial evolution on carbon-climate feedbacks in this system. We begin by reviewing the current state of knowledge concerning microbial evolution in response to global change and its specific effect on soil carbon dynamics. Through this integration, we synthesize a roadmap detailing how to integrate microbial evolution into ecosystem biogeochemical models. Specifically, we highlight the importance of microscale mechanistic soil carbon models, including choosing an appropriate evolutionary model (e.g., adaptive dynamics, quantitative genetics), validating model predictions with 'omics' and experimental data, scaling microbial adaptations to ecosystem level processes, and validating with ecosystem-scale measurements. The proposed steps will require significant investment of scientific resources and might require 10-20 years to be fully implemented. However, through the application of multi-scale integrated approaches, we will advance the integration of microbial evolution into predictive understanding of ecosystems, providing clarity on its role and impact within the broader context of environmental change.


Assuntos
Ecossistema , Microbiologia do Solo , Solo , Carbono , Clima
11.
Afr J Reprod Health ; 28(3): 74-80, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38583069

RESUMO

This study examines the nexus among political factors, carbon emissions, and life expectancy between 1990 and 2020 in India. Data for this study was extracted from the World Bank Development indicators, after which it was subjected to econometrics analysis. The results showed that on averages, between 1990 and 2020, India experienced a life expectancy around 65 years. Fossil fuel energy consumption represents a small proportion of total energy consumption in India. However, carbon emissions and life expectancy have a positive and significant relationship. Fossil fuel usage and life expectancy possess a significantly positive relationship (FFEC = 0.044128, P-value = 0.0023) Moreover, government effectiveness and life expectancy have a significant direct relationship. Political stability and life expectancy have a significant negative relationship in the country. We conclude that policymakers in India should ensure that carbon emissions and fossil fuel usage in India do not pose a threat to life expectancy. Efforts should be put in place by policymakers in India to increase life expectancy , a strategic component of SDG 3- good health and well being for all at all ages, by ensuring stable political climate, good governance and efficient health enhanced public policies.


Cette étude examine le lien entre les facteurs politiques, les émissions de carbone et l'espérance de vie entre 1990 et 2020 en Inde. Les données de cette étude ont été extraites des indicateurs de développement de la Banque mondiale, après quoi elles ont été soumises à une analyse économétrique. Les résultats ont montré qu'en moyenne, entre 1990 et 2020, l'Inde a connu une espérance de vie d'environ 65 ans. La consommation d'énergie fossile représente une petite proportion de la consommation totale d'énergie en Inde. Cependant, les émissions de carbone et l'espérance de vie ont une relation positive et significative. L'utilisation de combustibles fossiles et l'espérance de vie possèdent une relation significativement positive (FFEC = 0,044128, valeur P = 0,0023). De plus, l'efficacité du gouvernement et l'espérance de vie ont une relation directe significative. La stabilité politique et l'espérance de vie ont une relation négative significative dans le pays. Nous concluons que les décideurs politiques indiens devraient veiller à ce que les émissions de carbone et l'utilisation de combustibles fossiles en Inde ne constituent pas une menace pour l'espérance de vie. Des efforts devraient être mis en place par les décideurs politiques indiens pour augmenter l'espérance de vie, une composante stratégique de l'ODD 3 - bonne santé et bien-être pour tous à tout âge, en garantissant un climat politique stable, une bonne gouvernance et des politiques publiques efficaces et améliorées en matière de santé.


Assuntos
Carbono , Desenvolvimento Sustentável , Humanos , Combustíveis Fósseis , Política , Expectativa de Vida , Índia
12.
Sci Rep ; 14(1): 7899, 2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570566

RESUMO

Hutchison's niche theory suggests that coexisting competing species occupy non-overlapping hypervolumes, which are theoretical spaces encompassing more than three dimensions, within an n-dimensional space. The analysis of multiple stable isotopes can be used to test these ideas where each isotope can be considered a dimension of niche space. These hypervolumes may change over time in response to variation in behaviour or habitat, within or among species, consequently changing the niche space itself. Here, we use isotopic values of carbon and nitrogen of ten amino acids, as well as sulphur isotopic values, to produce multi-isotope models to examine niche segregation among an assemblage of five coexisting seabird species (ancient murrelet Synthliboramphus antiquus, double-crested cormorant Phalacrocorax auritus, Leach's storm-petrel Oceanodrama leucorhoa, rhinoceros auklet Cerorhinca monocerata, pelagic cormorant Phalacrocorax pelagicus) that inhabit coastal British Columbia. When only one or two isotope dimensions were considered, the five species overlapped considerably, but segregation increased in more dimensions, but often in complex ways. Thus, each of the five species occupied their own isotopic hypervolume (niche), but that became apparent only when factoring the increased information from sulphur and amino acid specific isotope values, rather than just relying on proxies of δ15N and δ13C alone. For cormorants, there was reduction of niche size for both species consistent with a decline in their dominant prey, Pacific herring Clupea pallasii, from 1970 to 2006. Consistent with niche theory, cormorant species showed segregation across time, with the double-crested demonstrating a marked change in diet in response to prey shifts in a higher dimensional space. In brief, incorporating multiple isotopes (sulfur, PC1 of δ15N [baselines], PC2 of δ15N [trophic position], PC1 and PC2 of δ13C) metrics allowed us to infer changes and differences in food web topology that were not apparent from classic carbon-nitrogen biplots.


Assuntos
Aminoácidos , Charadriiformes , Animais , Aminoácidos/metabolismo , Isótopos/metabolismo , Aves/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo , Enxofre/metabolismo , Isótopos de Nitrogênio/metabolismo , Isótopos de Carbono/metabolismo
13.
Sci Rep ; 14(1): 7885, 2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570698

RESUMO

SbtB is a PII-like protein that regulates the carbon-concentrating mechanism (CCM) in cyanobacteria. SbtB proteins can bind many adenyl nucleotides and possess a characteristic C-terminal redox sensitive loop (R-loop) that forms a disulfide bridge in response to the diurnal state of the cell. SbtBs also possess an ATPase/ADPase activity that is modulated by the redox-state of the R-loop. To investigate the R-loop in the cyanobacterium Synechocystis sp. PCC 6803, site-specific mutants, unable to form the hairpin and permanently in the reduced state, and a R-loop truncation mutant, were characterized under different inorganic carbon (Ci) and light regimes. Growth under diurnal rhythm showed a role of the R-loop as sensor for acclimation to changing light conditions. The redox-state of the R-loop was found to impact the binding of the adenyl-nucleotides to SbtB, its membrane association and thereby the CCM regulation, while these phenotypes disappeared after truncation of the R-loop. Collectively, our data imply that the redox-sensitive R-loop provides an additional regulatory layer to SbtB, linking the CO2-related signaling activity of SbtB with the redox state of cells, mainly reporting the actual light conditions. This regulation not only coordinates CCM activity in the diurnal rhythm but also affects the primary carbon metabolism.


Assuntos
Carbono , Synechocystis , Carbono/metabolismo , Estruturas R-Loop , Synechocystis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Nucleotídeos/metabolismo , Oxirredução , Dióxido de Carbono/metabolismo , Fotossíntese
14.
Sci Rep ; 14(1): 7824, 2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570696

RESUMO

Monoculture switchgrass and restored prairie are promising perennial feedstock sources for bioenergy production on the lands unsuitable for conventional agriculture. Such lands often display contrasting topography that influences soil characteristics and interactions between plant growth and soil C gains. This study aimed at elucidating the influences of topography and plant systems on the fate of C originated from switchgrass plants and on its relationships with soil pore characteristics. For that, switchgrass plants were grown in intact soil cores collected from two contrasting topographies, namely steep slopes and topographical depressions, in the fields in multi-year monoculture switchgrass and restored prairie vegetation. The 13C pulse labeling allowed tracing the C of switchgrass origin, which X-ray computed micro-tomography enabled in-detail characterization of soil pore structure. In eroded slopes, the differences between the monoculture switchgrass and prairie in terms of total and microbial biomass C were greater than those in topographical depressions. While new switchgrass increased the CO2 emission in depressions, it did not significantly affect the CO2 emission in slopes. Pores of 18-90 µm Ø facilitated the accumulation of new C in soil, while > 150 µm Ø pores enhanced the mineralization of the new C. These findings suggest that polyculture prairie located in slopes can be particularly beneficial in facilitating soil C accrual and reduce C losses as CO2.


Assuntos
Panicum , Solo , Solo/química , Carbono/química , Dióxido de Carbono , Pradaria , Plantas
15.
PLoS One ; 19(4): e0298266, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38573921

RESUMO

A mechanical device inspired by the pistol shrimp snapper claw was developed. This technology features a claw characterized by a periodic opening/closing motion, at a controlled frequency, capable of producing oscillating flows at transitional Reynolds numbers. An innovative method was also proposed for determining the corrosion rate of carbon steel samples under oscillating acidic streams (aqueous solution of HCl). By employing very-thin carbon steel specimens (25 µm thickness), with one side coated with Zn and not exposed to the stream, it became possible to electrochemically sense the Zn surface once the steel sample was perforated, thus providing the average dissolution rate into the most relevant pit on the steel surface. Furthermore, a laser light positioned beneath the metallic sample, along with a camera programmed to periodically capture images of the steel surface, facilitated the accurate counting of the number of newly formed pits. The system consisting of the thin steel sample and the Zn coating can be seen as a type of corrosion sensor. Furthermore, the proposed laser illumination method allows corroborating the electrochemical detection of pits and also establishing their location. The techniques crafted in this study pave the way for developing alternative corrosion sensors that boast appealing attributes: affordability, compactness, and acceptable accuracy to detect in time and space localized damage.


Assuntos
Carbono , Aço , Carbono/química , Aço/química , Corrosão , Rios , Ácidos/química
16.
PLoS One ; 19(4): e0299727, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38573973

RESUMO

The effect of carbon emissions on the environment has made some of the Sustainable Development Goals difficult to achieve. Despite the efforts of international bodies, there is still a need to address the problem since the transition is not complete. Therefore, this study investigates the effect of globalization, economic growth, financial inclusion, renewable energy, and government institutions on carbon emissions from the period of 1998 to 2021. To be able to assess both the direct and indirect effects of the variables, the Partial Least Square Structural Equation Modelling is employed, where renewable energy serves as the mediator, and the Two-Stage Least Squares is employed as the robustness check. The findings of the study reveal that globalization promotes the use of renewable energy, but financial inclusion has a negative effect on renewable energy use. Renewable energy has a direct positive and significant effect on carbon emissions. Financial inclusion has an indirect negative and significant effect on carbon emissions. The results imply that more enlightenment on financial inclusion will help a smooth transition, and globalization should be embraced when all environmental regulations are enforced.


Assuntos
Carbono , Desenvolvimento Econômico , Análise de Classes Latentes , Análise dos Mínimos Quadrados , Energia Renovável , Dióxido de Carbono , Internacionalidade
17.
PLoS One ; 19(4): e0300595, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38573988

RESUMO

Green and low carbon reflect the high-quality development, while income distribution is an indicator of the balance of development. Is there a lack of fairness in the process of green and low carbon transition of enterprises? Using data from A-share listed companies from 2009 to 2016, this paper constructs a DID identification framework for controlling the endogeneity problem using the 2013 carbon trading policy pilot as a quasi-natural experiment to empirically test the impact of corporate low-carbon transformation on corporate labor income share in the context of carbon trading policy. The findings indicate that carbon trading policy decreases the labor income share of firms. In addition, we demonstrate that the low-carbon transition promotes labor productivity, suggesting that the Porter's hypothesis is confirmed in China, but the increase in labor wages is not in tandem with productivity growth, resulting in reduced labor income share. Heterogeneity analysis shows that the impact of carbon trading policy on labor income share is mainly pronounced in larger firms, high technology firms and persistent incumbent firms. Collectively, these results are expected to accurately improve our understanding on the impact of low-carbon transformation of enterprises on income distribution and provide reference for the government to formulate industrial policies and distribution mechanisms under low-carbon economy.


Assuntos
Carbono , Renda , China , Governo , Indústrias
18.
PLoS One ; 19(4): e0299054, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38574027

RESUMO

Wheat straw returning is widely practiced in agriculture; therefore, it is critical to determine the physicochemical and bacterial indicators in soil for the organic carbon storage, accumulative C mineralization, total nitrogen improvement, and nitrogen mineralization in various soil types after wheat straw returning. This study evaluated the influenced indicators of wheat straw addition on soil organic carbon and nitrogen transformation in diverse soil types. For this purpose, an incubation experiment was conducted to analyze the carbon and nitrogen transformation in soil from eight Chinese provinces treated with the same dry weight of wheat straw. The results indicated that the primary physicochemical and bacterial indicators that predict the carbon and nitrogen transformations in the acidic and alkaline soils were different. Of all the natural physicochemical properties of soil, cation exchange capacity and clay content were significantly correlated with organic carbon, mineralized carbon, total nitrogen, and mineralized nitrogen in the alkaline soil. In the acidic soil, the initial C/N ratio of soil was the most significant indicator of carbon and nitrogen transformation. From the perspective of the carbon- and nitrogen-relating bacterial communities, Proteobacteria were largely responsible for the accumulative C mineralization in both types of soil. Furthermore, Proteobacteria strongly regulated the organic carbon storage in the acidic soil after wheat straw addition, whereas Gemmatimonadetes was the main predicted indicator in the alkaline soil. Additionally, total nitrogen and mineralized nitrogen levels were largely explained by Bifidobacterium and Luteimonas in the alkaline soil and by Nitrospira and Bdellovibrio in the acidic soil. Soil physicochemical and biological properties significantly influence soil carbon and nitrogen transformation, which should be considered crucial indicators to guide the rational regulation of straw return in several areas.


Assuntos
Carbono , Solo , Solo/química , Triticum , Nitrogênio/análise , Agricultura/métodos , Bactérias , Proteobactérias , Fertilizantes
19.
Fungal Biol ; 128(2): 1664-1674, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38575239

RESUMO

Although tyrosol is a quorum-sensing molecule of Candida species, it has antifungal activity at supraphysiological concentrations. Here, we studied the effect of tyrosol on the physiology and genome-wide transcription of Aspergillus nidulans to gain insight into the background of the antifungal activity of this compound. Tyrosol efficiently reduced germination of conidia and the growth on various carbon sources at a concentration of 35 mM. The growth inhibition was fungistatic rather than fungicide on glucose and was accompanied with downregulation of 2199 genes related to e.g. mitotic cell cycle, glycolysis, nitrate and sulphate assimilation, chitin biosynthesis, and upregulation of 2250 genes involved in e.g. lipid catabolism, amino acid degradation and lactose utilization. Tyrosol treatment also upregulated genes encoding glutathione-S-transferases (GSTs), increased specific GST activities and the glutathione (GSH) content of the cells, suggesting that A. nidulans can detoxify tyrosol in a GSH-dependent manner even though this process was weak. Tyrosol did not induce oxidative stress in this species, but upregulated "response to nutrient levels", "regulation of nitrogen utilization", "carbon catabolite activation of transcription" and "autophagy" genes. Tyrosol may have disturbed the regulation and orchestration of cellular metabolism, leading to impaired use of nutrients, which resulted in growth reduction.


Assuntos
Antifúngicos , Aspergillus nidulans , Álcool Feniletílico/análogos & derivados , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Transcriptoma , Glutationa/genética , Glutationa/metabolismo , Glutationa/farmacologia , Carbono/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
20.
Sci Rep ; 14(1): 7926, 2024 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575619

RESUMO

Nanofibers are investigated to be superiorly applicable in different purposes such as drug delivery systems, air filters, wound dressing, water filters, and tissue engineering. Herein, polyacrylonitrile (PAN) is thermally treated for autocatalytic cyclization, to give optically active PAN-nanopolymer, which is subsequently applicable for preparation of nanofibers through solution blow spinning. Whereas, solution blow spinning is identified as a process for production of nanofibers characterized with high porosity and large surface area from a minimum amounts of polymer solution. The as-prepared nanofibers were shown with excellent photoluminescence and microbicide performance. According to rheological properties, to obtain spinnable PAN-nanopolymer, PAN (12.5-15% wt/vol, honey like solution, 678-834 mPa s), thermal treatment for 2-4 h must be performed, whereas, time prolongation resulted in PAN-nanopolymer gelling or rubbering. Size distribution of PAN-nanopolymer (12.5% wt/vol) is estimated (68.8 ± 22.2 nm), to reflect its compatibility for the production of carbon nanofibers with size distribution of 300-400 nm. Spectral mapping data for the photoluminescent emission showed that, PAN-nanopolymer were exhibited with two intense peaks at 498 nm and 545 nm, to affirm their superiority for production of fluorescent nanofibers. The microbial reduction % was estimated for carbon nanofibers prepared from PAN-nanopolymer (12.5% wt/vol) to be 61.5%, 71.4% and 81.9%, against S. aureus, E. coli and C. albicans, respectively. So, the prepared florescent carbon nanofibers can be potentially applicable in anti-infective therapy.


Assuntos
Resinas Acrílicas , Anti-Infecciosos , Nanofibras , Escherichia coli , Staphylococcus aureus , Desenvolvimento Industrial , Candida albicans , Carbono
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...