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Braz. j. biol ; 84: e256425, 2024. tab, graf, mapas
Article in English | LILACS, VETINDEX | ID: biblio-1364525


Using inventory data, this study evaluates the species composition, growing stock volume (GSV), and biomass carbon (BMC) of the five major timber species in the sub-tropical, and temperate/sub-alpine regions of Pakistan. It was found that the stem density varies between 50 and 221 trees ha -1, with a mean of 142 trees ha-1 (13.68 million trees for entire forest area). Among the species, Pinus wallichiana showed a high species composition (27.80%) followed by Picea smithiana (24.64%). The GSV was found in the range of 67.81 to 425.94 m3 ha-1, with a total GSV value of 20.68 million m3 for the entire region. Similarly, The BMC ranged from 27.04 to 169.86 Mg ha-1, with a mean BMC value of 86.80 Mg ha-1. The total amount of stored carbon was found at 8.69 million tons for a total of 95842 ha of commercially managed forest. Furthermore, the correlation analysis between the basal area (BA) and GSV and BMC showed that BA is the best predictor of GSV and BMC. The findings provide insights to the policy makers and forest managers regarding the sustainable commercial forest management as well as forest carbon management in the recent global carbon management for climate change mitigation.

Usando dados de inventário, este estudo avaliou a composição de espécies, volume de estoque crescente (GSV) e carbono de biomassa (BMC) das cinco principais espécies madeireiras nas regiões subtropicais e temperadas/subalpinas do Paquistão. Constatou-se que a densidade do caule variou entre 50 e 221 árvores ha-1, com média de 142 árvores ha-1 (13,68 milhões de árvores para toda a área florestal). Entre as espécies, Pinus wallichiana apresentou alta composição de espécies (27,80%), seguida de Picea smithiana (24,64%). O GSV foi encontrado na faixa de 67,81 a 425,94 m3 ha-1, com um valor total de 20,68 milhões de m3 para toda a região. Da mesma forma, o BMC variou de 27,04 a 169,86 mg ha-1, com valor médio de 86,80 mg ha-1. A quantidade total de carbono armazenado foi de 8,69 milhões de toneladas para um total de 95.842 ha de floresta manejada comercialmente. Além disso, a análise de correlação entre área basal (BA), GSV e BMC mostrou que BA é o melhor preditor de GSV e BMC. As descobertas fornecem insights para os formuladores de políticas e gestores florestais sobre o manejo florestal comercial sustentável, bem como o manejo florestal de carbono no recente gerenciamento global de carbono para a mitigação das mudanças climáticas.

Trees/growth & development , Carbon , Forests , Biomass
Braz. j. biol ; 83: e249424, 2023. graf
Article in English | LILACS, VETINDEX | ID: biblio-1345538


Abstract Hypoxia is a prominent feature of head and neck cancer. However, the oxygen element characteristics of proteins and how they adapt to hypoxia microenvironments of head and neck cancer are still unknown. Human genome sequences and proteins expressed data of head and neck cancer were retrieved from pathology atlas of Human Protein Atlas project. Then compared the oxygen and carbon element contents between proteomes of head and neck cancer and normal oral mucosa-squamous epithelial cells, genome locations, pathways, and functional dissection associated with head and neck cancer were also studied. A total of 902 differentially expressed proteins were observed where the average oxygen content is higher than that of the lowly expressed proteins in head and neck cancer proteins. Further, the average oxygen content of the up regulated proteins was 2.54% higher than other. None of their coding genes were distributed on the Y chromosome. The up regulated proteins were enriched in endocytosis, apoptosis and regulation of actin cytoskeleton. The increased oxygen contents of the highly expressed and the up regulated proteins might be caused by frequent activity of cytoskeleton and adapted to the rapid growth and fast division of the head and neck cancer cells. The oxygen usage bias and key proteins may help us to understand the mechanisms behind head and neck cancer in targeted therapy, which lays a foundation for the application of stoichioproteomics in targeted therapy and provides promise for potential treatments for head and neck cancer.

Resumo A hipóxia é uma característica proeminente do câncer de cabeça e pescoço. No entanto, as características do elemento oxigênio das proteínas e como elas se adaptam aos microambientes de hipóxia do câncer de cabeça e pescoço ainda são desconhecidas. Sequências do genoma humano e dados expressos de proteínas de câncer de cabeça e pescoço foram recuperados do atlas de patologia do projeto Human Protein Atlas. Em seguida, comparou o conteúdo do elemento de oxigênio e carbono entre proteomas de câncer de cabeça e pescoço, e células epiteliais escamosas da mucosa oral normal, localizações do genoma, vias e dissecção funcional associada ao câncer de cabeça e pescoço também foram estudadas. Um total de 902 proteínas expressas diferencialmente foi observado onde o conteúdo médio de oxigênio é maior do que as proteínas expressas de forma humilde em proteínas de câncer de cabeça e pescoço. Além disso, o conteúdo médio de oxigênio das proteínas reguladas positivamente foi 2,54% maior do que das outras. Nenhum de seus genes codificadores foi distribuído no cromossomo Y. As proteínas reguladas positivamente foram enriquecidas em endocitose, apoptose e regulação do citoesqueleto de actina. O conteúdo aumentado de oxigênio das proteínas altamente expressas e reguladas pode ser causado pela atividade frequente do citoesqueleto e adaptado ao rápido crescimento e divisão das células cancerosas de cabeça e pescoço. O viés do uso de oxigênio e as proteínas-chave podem nos ajudar a entender os mecanismos por trás do câncer de cabeça e pescoço na terapia direcionada, o que estabelece uma base para a aplicação da estequioproteômica na terapia direcionada e oferece uma promessa para potenciais tratamentos para o câncer de cabeça e pescoço.

Humans , Head and Neck Neoplasms/genetics , Oxygen , Carbon , Proteome/genetics , Tumor Microenvironment
Chinese Journal of Biotechnology ; (12): 2410-2429, 2023.
Article in Chinese | WPRIM | ID: wpr-981209


The current linear economy model relies on fossil energy and increases CO2 emissions, which contributes to global warming and environmental pollution. Therefore, there is an urgent need to develop and deploy technologies for carbon capture and utilization to establish a circular economy. The use of acetogens for C1-gas (CO and CO2) conversion is a promising technology due to high metabolic flexibility, product selectivity, and diversity of the products including chemicals and fuels. This review focuses on the physiological and metabolic mechanisms, genetic and metabolic engineering modifications, fermentation process optimization, and carbon atom economy in the process of C1-gas conversion by acetogens, with the aim to facilitate the industrial scale-up and carbon negative production through acetogen gas fermentation.

Fermentation , Gases/metabolism , Carbon Dioxide/metabolism , Metabolic Engineering , Carbon/metabolism
Chinese Journal of Biotechnology ; (12): 2101-2107, 2023.
Article in Chinese | WPRIM | ID: wpr-981192


Engineering efficient enzymes or microbial cell factories should help to establish green bio-manufacturing process for chemical overproduction. The rapid advances and development in synthetic biology, systems biology and enzymatic engineering accerleate the establishing feasbile bioprocess for chemical biosynthesis, including expanding the chemical kingdom and improving the productivity. To consolidate the latest advances in chemical biosynthesis and promote green bio-manufaturing, we organized a special issue on chemical bioproduction that including review or original research papers about enzymatic biosynthesis, cell factory, one-carbon based biorefinery and feasible strategies. These papers comprehensively discussed the latest advaces, the challenges as well as the possible solutions in chemical biomanufacturing.

Synthetic Biology , Carbon , Metabolic Engineering
Chinese Journal of Biotechnology ; (12): 2053-2069, 2023.
Article in Chinese | WPRIM | ID: wpr-981189


In recent years, the petroleum-based plastic pollution problem has been causing global attention. The idea of "degradation and up-cycling of plastics" was proposed for solving the environmental pollution caused by non-degradable plastics. Following this idea, plastics would be firstly degraded and then reconstructed. Polyhydroxyalkanoates (PHA) can be produced from the degraded plastic monomers as a choice to recycle among various plastics. PHA, a family of biopolyesters synthesized by many microbes, have attracted great interest in industrial, agricultural and medical sectors due to its biodegradability, biocompatibility, thermoplasticity and carbon neutrality. Moreover, the regulations on PHA monomer compositions, processing technology, and modification methods may further improve the material properties, making PHA a promising alternative to traditional plastics. Furthermore, the application of the "next-generation industrial biotechnology (NGIB)" utilizing extremophiles for PHA production is expected to enhance the PHA market competitiveness, promoting this environmentally friendly bio-based material to partially replace petroleum-based products, and achieve sustainable development with carbon-neutrality. This review summarizes the basic material properties, plastic upcycling via PHA biosynthesis, processing and modification methods of PHA, and biosynthesis of novel PHA.

Polyhydroxyalkanoates , Plastics , Biotechnology , Petroleum , Carbon
Chinese Journal of Biotechnology ; (12): 1040-1055, 2023.
Article in Chinese | WPRIM | ID: wpr-970421


Typical solid wastes contain many metal resources, which are worthy of recycling. The bioleaching of typical solid waste is affected by multiple factors. Green and efficient recovery of metals based on the characterization of leaching microorganisms and the elucidation of leaching mechanisms may contribute to the implementation of China's "dual carbon" strategic goals. This paper reviews various types of microorganisms used for leaching metals from typical solid wastes, analyzes the action mechanism of metallurgical microorganisms, and prospects the application of metallurgical microorganisms to facilitate the application of metallurgical microorganisms in typical solid wastes.

Solid Waste , Metals , Metallurgy , Carbon
Chinese Journal of Epidemiology ; (12): 353-359, 2023.
Article in Chinese | WPRIM | ID: wpr-969913


Climate change is the great health challenge for human beings in the 21st century. Air pollution is also an important public health problem worldwide. China announced the climate commitment to achieve carbon peaking by 2030 and carbon neutrality by 2060. Achieving these goals would not only have far-reaching effects on air pollution control and climate change, but also improve the population health in China. Air pollution and climate change epidemiology are important aspects of environmental epidemiology. In this paper, we discuss the current status and future development of epidemiological research of air pollution and climate change in the context of achieving carbon peaking and carbon neutrality goals to provide ideas and suggestions for environmental and health studies in the future.

Humans , Climate Change , Goals , Air Pollution/analysis , Environmental Health , Public Health , China/epidemiology , Carbon
Braz. j. biol ; 83: e246002, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1285612


Abstract Economic valuation of ecosystem services is a new concept in forest management. Economic valuation provides basis for payment for ecosystem services (PES). Therefore, objective of this study was to evaluate eco-tourism and carbon stock services of the Maindam valley, District Swat, Pakistan. For the carbon stock calculation, a sample size of 155 plots of 0.1 hectare (Ha) was taken using preliminary survey at 95% confidence interval and 10% allowable error. The data for tourism services was collected from owners of all the hotels, 100 tourists and key informants of the area at 10% sampling intensity on pretested questionnaire for twenty years period (1997-2017). Results showed that Miandam valley has carbon stock worth US$ 16,306,000 while the value of eco-tourism was US$ 1,578,458 on annual basis. The results also showed that trend of tourism has drastically declined after the 9/11 incident for foreigners and locals and the situation was further deteriorated during the era of Talibanization or militancy from 2008-2011. This study recommends implementation of PES strategy at the rate of 5%, thus a total of US$ 78,922 can be earned from eco-tourism and carbon crediting in the study area annually, which could play important role in sustainable forest management.

Resumo A valoração econômica dos serviços ecossistêmicos é um novo conceito no manejo florestal. A avaliação econômica fornece base para o pagamento por serviços ecossistêmicos (PES). Portanto, o objetivo deste estudo foi avaliar o ecoturismo e os serviços de estoque de carbono do vale de Miandam, distrito Swat, Paquistão. Para o cálculo do estoque de carbono, um tamanho de amostra de 155 parcelas de 0,1 hectare (ha) foi tirado, usando pesquisa preliminar com intervalo de confiança de 95% e erro admissível de 10%. Os dados para serviços de turismo foram coletados de proprietários de todos os hotéis, 100 turistas e informantes-chave da área em 10% de intensidade de amostragem em questionário pré-testado para um período de 20 anos (1997-2017). Os resultados mostraram que o vale de Miandam tem estoque de carbono no valor de US$ 16.306.000, enquanto o valor do ecoturismo foi de US$ 1.578.458 anualmente. Os resultados também mostraram que a tendência do turismo diminuiu drasticamente para estrangeiros e locais após o incidente de 11 de Setembro, e a situação se agravou ainda mais durante a era da talibanização ou militância de 2008-2011. Este estudo recomenda a implementação da estratégia de PES na taxa de 5%, portanto um total de US$ 78.922 pode ser ganho com ecoturismo e crédito de carbono na área de estudo anualmente, o que pode desempenhar um papel importante no manejo florestal sustentável.

Ecosystem , Conservation of Natural Resources , Pakistan , Carbon/analysis , Forests
Arq. Asma, Alerg. Imunol ; 6(2): 256-261, abr.jun.2022. ilus
Article in English, Portuguese | LILACS | ID: biblio-1400206


A pandemia de COVID-19 deu ao mundo uma imagem clara do que é uma crise multidimensional em escala planetária, revelando o papel central que ocupa o setor de saúde e as profundas desigualdades no acesso aos cuidados em saúde que existem entre os diferentes países, e dentro de cada um deles. Melhorar os efeitos ambientais do setor e reduzir as emissões de gases de efeito estufa pode não apenas melhorar a saúde de todos, mas também reduzir os custos com os cuidados em saúde. O setor de saúde de cada país libera direta e indiretamente gases de efeito estufa ao fornecer seus serviços e ao comprar produtos, serviços e tecnologias em uma cadeia de fornecimento de carbono intensivo. Educar os profissionais de saúde mais profundamente sobre os efeitos das mudanças climáticas pode levar a práticas clínicas mais sustentáveis, melhorando os resultados para os pacientes e fornecendo um impulso substancial para aumentar os esforços para reduzir as emissões de carbono. O setor da saúde deve assumir a responsabilidade por sua pegada climática respondendo à crescente emergência climática, não apenas prestando assistência aos doentes, feridos ou moribundos como resultado da crise climática e suas causas, mas também fazendo a prevenção primária e reduzindo drasticamente suas próprias emissões.

The COVID-19 pandemic has painted a clear picture of what a multidimensional planetary crisis is, revealing the central role played by the health sector and the deep inequalities in access to health care that exist between and within each country. Decreasing the environmental effects of the health sector and reducing greenhouse gas emission may not only improve people's health, but also reduce health care costs. The health care sectors around the world directly and indirectly release greenhouse gases by providing their services and purchasing products, services, and technologies within a carbon-intensive supply chain. Further educating health care professionals about the effects of climate change may lead to more sustainable clinical practices, improving patient outcomes and providing substantial impetus to increased efforts to reduce carbon emission. The health sector must take responsibility for its climate footprint by responding to the growing climate emergency not only by assisting the sick, injured, or dying from the climate crisis, but also by doing primary prevention and drastically reducing its own carbon emission.

Humans , Climate Change , Environmental Health , COVID-19 , Patients , Primary Prevention , Carbon , Health , Health Care Costs , Climate , Health Personnel , Greenhouse Effect , PubMed , Greenhouse Gases , Pandemics , Health Services Accessibility
China Journal of Chinese Materia Medica ; (24): 1824-1830, 2022.
Article in Chinese | WPRIM | ID: wpr-928178


Leaf blight outbroke in Rehmannia glutinosa plantation in Wenxian county, Henan province in 2019. R. glutinosa plants with diseased leaves were collected from the plantation, and three strains were isolated from the diseased leaf samples. Pathogenicity test, morphological observation, and phylogenetic analysis of ITS, EF1-α, and Tub suggested that they were respectively Fusarium proliferatum, F. oxysporum, and F.acuminatum. Among them, F. acuminatum, as a pathogen of R. glutinosa leaf disease, had never been reported. To clarify the biological characteristics of F. acuminatum, this study tested the influence of light, pH, temperature, medium, carbon source, and nitrogen source on the mycelial growth rate of the pathogen during a 5-day culture period, and explored the lethal temperature. The results showed that the mycelia grew well under the photoperiod of 12 h light/12 h darkness, at 5-40 ℃(optimal temperature: 25 ℃), at pH 4-11(optimal pH: 7.0), on a variety of media(optimal medium: oatmeal agar), and in the presence of diverse carbon and nitrogen sources(optimal carbon source: soluble starch; optimal nitrogen source: sodium nitrate). The lethal temperature was verified to be 51 ℃(10 min). The conclusion is expected to lay a scientific basis for diagnosis and control of R. glutinosa leaf diseases caused by F. acuminatum.

Carbon , Nitrogen , Phylogeny , Rehmannia
Chinese Journal of Burns ; (6): 697-700, 2022.
Article in Chinese | WPRIM | ID: wpr-940977


Chronic and infectious wound healing has always been an issue of concern in clinical and scientific research, in which bacterial infection and oxidative damage are the key factors hindering wound healing. Carbon dots, as a new material, has attracted much attention because of its unique physical and chemical properties and good biological safety. In recent years, the researches on the antibacterial property, antioxidant, and photoluminescence properties of carbon dots are more and more extensive and carbon dots have great potential in the treatment of chronic and infectious wounds. This paper reviews the research progress of carbon dots in three aspects: antibacterial, anti-oxidation and monitoring of wound infection are reviewed, and further discusses its specific mechanism, potential research direction, and application prospect.

Humans , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Carbon/therapeutic use , Wound Healing , Wound Infection/drug therapy
Ciênc. rural (Online) ; 52(10): 20200845, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1364717


Integrated agricultural production systems have the potential to increase organic matter content, which is reflected in the soil carbon (C) and nitrogen (N) concentrations. Here, we evaluated the C and N stocks and its compartments in a typical distro cohesive yellow Ultisol under the no-till (NT) and crop-livestock integration (CLI) systems, in eastern Maranhão. Five areas with different management strategies were evaluated, more specifically, one area was managed under the NT system in succession for 14 years (soybean/millet), three areas had different CLI system adoption histories (i.e., CLI was adopted 2, 4, or 8 years prior to sample collection); and finally, one area consisted of native Cerrado (savannah) vegetation. Soil samples were collected at depths of 0-0.10, 0.10-0.20, 0.20-0.30, and 0.30-0.50 m,to analyze the content and total stocks of carbon (C) and its compartments (physical and chemical), N content, soil microbial biomass, and basal respiration. Results revealed higher content and stock of C and N in areas with CLI. The principal humic substance reported was humin, and higher concentrations of C associated with minerals were present in areas under more recent CLI adoption (2 and 4 years). We demonstrated that the adoption of CLI, even if recent, leads to immediate increases in the concentrations of C and its fractions as a result of using forage crops. NT for 14 years and CLI for 8 years exhibited higher levels of C management and higher soil biological activity due to the greater stability of these systems.

Os sistemas integrados de produção agropecuária possuem potencial de incrementar a matéria orgânica, com reflexos nas concentrações de carbono e de nitrogênio no solo. O objetivo do trabalho foi avaliar estoques de carbono e nitrogênio e seus compartimentos em um Argissolo Amarelo Distrocoeso típico sob plantio direto e integração lavoura-pecuária no Leste maranhense. Os manejos avaliados foram: sistema de plantio direto em sucessão há 14 anos (soja/milheto), três áreas com diferentes históricos de sucessão com a adoção do sistema integração lavoura-pecuária (ILP), sendo dois, quatro e oito anos, além de uma área de Cerrado nativo. Foram coletadas amostras de solo nas profundidades de 0,00-0,10; 0,10-0,20; 0,20-0,30; 0,30-0,50 metros para análise de teores e estoques totais de carbono (C) e de seus compartimentos (físico e químico), nitrogênio (N) e da biomassa microbiana do solo e respiração basal. Os resultados revelam maior teor e estoque de C e N nas áreas com ILP. A substância húmica predominante foi a humina e maiores concentrações do carbono associado a minerais estiveram presentes na área sob ILP mais recente (dois e quatro anos). A adoção da ILP, mesmo que recente, proporciona incrementos imediatos nas concentrações de C e suas frações em função do emprego de forrageiras. O plantio direto há 14anos e ILP há oito anos são sistemas com maior índice de manejo do C, como, também, apresentam maior atividade biológica do solo, devido à maiores estabilidade destes sistemas.

Carbon/analysis , Agricultural Cultivation , Soil Analysis , Soil Chemistry , Animal Husbandry/methods
Chinese Journal of Biotechnology ; (12): 1527-1536, 2022.
Article in Chinese | WPRIM | ID: wpr-927798


Halomonas can grow on diverse carbon sources. As it can be used for unsterile fermentation under high-salt conditions, it has been applied as a chassis for next-generation industrial biotechnology. Short-chain volatile fatty acids, including acetate, propionate, and butyrate, can be prepared from biomass and are expected to be novel carbon sources for microbial fermentation. Halomonas sp. TD01 and TD08 were subjected to shaking culture with 10-50 g/L butyrate, and they were found to effectively synthesize poly-3-hydroxybutyrate with butyrate as the carbon source. The highest yield of poly-3-hydroxybutyrate was achieved at butyrate concentration of 20 g/L (9.12 g/L and 7.37 g/L, respectively). Butyrate at the concentration > 20 g/L inhibited cell growth, and the yield of poly-3-hydroxybutyrate decreased to < 4 g/L when butyrate concentration was 50 g/L. Moreover, Halomonas sp. TD08 can accumulate the copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate by using propionate and butyrate as carbon sources. However, propionate was toxic to cells. To be specific, when 2 g/L propionate and 20 g/L butyrate were simultaneously provided, cell dry weight and polymer titer were 0.83 g/L and 0.15 g/L, respectively. The addition of glycerol significantly improved cell growth and boosted the copolymer titer to 3.95 g/L, with 3-hydroxyvalerate monomer content of 8.76 mol%. Short-chain volatile fatty acids would be promising carbon sources for the production of polyhydroxyalkanoates by Halomonas.

Butyrates , Carbon , Fatty Acids, Volatile , Halomonas , Polyhydroxyalkanoates , Propionates
Chinese Journal of Biotechnology ; (12): 1322-1338, 2022.
Article in Chinese | WPRIM | ID: wpr-927783


Aerobic methane oxidizing bacteria (methanotrophs) can use methane as carbon source and energy source, eliminating 10%-20% of global methane. Methanotrophs can also effectively synthesize valuable methane-derived products. This article introduced the methane oxidizing mechanism of methanotrophs, and summarized the practical application and research hotspots of methanotrophs in the field of methane emission reduction in the landfill, ventilation air methane mitigation in coal mines, valuable chemicals biosynthesis, as well as oil and gas reservoir exploration. Main factors influencing the pollutant removal and the biosynthesis efficiency in various applications were also discussed. Based on the study of large-scale cultivation of methanotrophs, some measures to benefit the application and promotion of aerobic methane oxidizing biotechnology were proposed. This includes investigating the effect of intermediate metabolites on methanotrophs activity and population structure, and exploiting economical and efficient alternative culture media and culture techniques.

Biotechnology , Carbon , Culture Media/chemistry , Methane/metabolism , Methylococcaceae/metabolism , Oxidation-Reduction
Chinese Journal of Biotechnology ; (12): 592-604, 2022.
Article in Chinese | WPRIM | ID: wpr-927730


Cyanobacteria are important photosynthetic autotrophic microorganisms and are considered as one of the most promising microbial chassises for photosynthetic cell factories. Glycogen is the most important natural carbon sink of cyanobacteria, playing important roles in regulating its intracellular carbon distributions. In order to optimize the performances of cyanobacterial photosynthetic cell factories and drive more photosynthetic carbon flow toward the synthesis of desired metabolites, many strategies and approaches have been developed to manipulate the glycogen metabolism in cyanobacteria. However, the disturbances on glycogen metabolism usually cause complex effects on the physiology and metabolism of cyanobacterial cells. Moreover, the effects on synthesis efficiencies of different photosynthetic cell factories usually differ. In this manuscript, we summarized the recent progress on engineering cyanobacterial glycogen metabolism, analyzed and compared the physiological and metabolism effects caused by engineering glycogen metabolism in different cyanobacteria species, and prospected the future trends of this strategy on optimizing cyanobacterial photosynthetic cell factories.

Carbon/metabolism , Carbon Dioxide/metabolism , Cyanobacteria/metabolism , Glycogen/metabolism , Metabolic Engineering , Photosynthesis/physiology
Biomedical and Environmental Sciences ; (12): 215-224, 2022.
Article in English | WPRIM | ID: wpr-927655


Objective@#To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes.@*Methods@#Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques.@*Results@#CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively.@*Conclusion@#The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.

Humans , Ammonium Compounds/chemical synthesis , Carbon/chemistry , Electrochemical Techniques , Enzymes , Fluorides/chemical synthesis , Nanostructures , Oxidation-Reduction
São Paulo; s.n; s.n; 2022. 191 p. tab, graf.
Thesis in English | LILACS | ID: biblio-1378632


The interaction of the organic ligands with metal nanoparticle has a very important role for applications in catalysis, as well as other processes involving ligands that can activate or poison the surface of metal nanoparticles. Very little has been studied so far on the role of organic ligands used either in the preparation of nanoparticles for applications in catalysis or addition in the reaction to activate the catalyst. In this thesis, we have studied strategies for the synthesis of metal nanoparticles, their use as components for the preparation of supported catalysts and activation and deactivation processes involving the ligands used as stabilizers or purposely added to the reaction medium or support for stimulate new reactivity and selectivity in reactions of industrial interest, such as hydrogenation. Here, the concept of frustrated Lewis pairs (FLPs) has been expanded to surface-FLP analogous formed by combining gold nanoparticles (NPs) and Lewis bases, such as amines or phosphines, creating a new channel for the heterolytic cleavage of H2, and thereby performing selective hydrogenation reactions with gold. A first approach to improve the catalytic activity of gold nanoparticles was to analyze the effect of nitrogen-containing bases. The starting inactive gold nanoparticles became highly active for the selective hydrogenation of alkyne into cis-alkenes. The hydrogenation proceeded smoothly and fully selective using H2 as the hydrogen source and under relatively mild conditions (80 °C, 6 bar H2). Our studies also have revealed that the presence of capping ligands blocks the adsorption of the amine to the gold surface, avoiding the FLPs interface and thereby leading to low catalytic activity. When the capping ligands were removed from the catalyst surface and an amine ligand was added, the FLPs interface is recovered and an enhanced catalytic activity was observed. Furthermore, we have demonstrated the successful use of simple organophosphorus ligands to boost the catalytic activity of Au NPs for a range of important reduction reactions, namely, epoxides, N-oxides, sulfoxides, and alkynes. Furthermore, the choice of phosphorus-containing ligands resulted in a decrease in the amount necessary to reach high conversion and selectivity in comparison with our previous study with N-containing ligands. The ligand-to-metal ratio decreased from 100 (amine/Au) to 1 (phosphite/Au). The synthesis of gold nanoparticles supported on N-doped carbon supports was used as an alternative method for the synthesis of a heterogeneous active gold catalyst for selective hydrogenations. The main advantage with respect to previous studies was to avoid the addition of external ligands, in large excess, for the activation of gold surfaces via FLP, making the whole process environmentally and economically attractive

A interação dos ligantes orgânicos com nanopartículas de metal certamente tem um papel muito importante para aplicações em catálise, bem como outros processos envolvendo ligantes que podem ativar ou envenenar a superfície de nanopartículas metálicas. Até agora, muito pouco foi estudado sobre o papel dos ligantes orgânicos utilizados na preparação de nanopartículas para aplicações em catálise ou adição na reação para ativar o catalisador. Nesta tese, foram estudadas estratégias para a síntese de nanopartículas metálicas, seu uso como componentes para a preparação de catalisadores suportados e processos de ativação e desativação envolvendo ligantes empregados como estabilizantes ou propositalmente adicionados ao meio de reação ou suporte para estimular novas reatividades e seletividade em reações de interesse industrial, como reações de hidrogenação. Aqui, o conceito de pares de Lewis frustrados (FLPs) foi expandido para o seu análogo de superfície formado pela combinação de nanopartículas (NPs) de ouro e bases de Lewis, como aminas ou fosfinas, criando um novo canal para a clivagem heterolítica de H2 e, assim, realizando reações seletivas de hidrogenação com ouro. Uma primeira abordagem para melhorar a atividade catalítica das nanopartículas de ouro foi analisar o efeito de bases contendo nitrogênio. As nanopartículas de ouro inicialmente inativas tornaram-se altamente ativas para a hidrogenação seletiva de alquino em cis-alquenos. A hidrogenação prosseguiu foi factível e totalmente seletiva usando H2 como fonte de hidrogênio e sob condições relativamente amenas (80 °C, 6 bar de H2). Nossos estudos também revelaram que a presença de estabilizantes pode bloquear a adsorção da base na superfície do ouro, impedindo a formação da interface FLPs e, portanto, levando a baixa atividade catalítica. Quando os estabilizantes foram removidos da superfície do catalisador e um ligante foi adicionado, o FLPs é formado sendo a atividade catalítica aprimorada. Além disso, demonstramos o uso bem-sucedido de ligantes organofosforados atuando como ativadores de Au NPs em uma série de importantes reações de redução, como, epóxidos, N-óxidos, sulfóxidos e alquinos. Além disso, a escolha do ligante fosforado resultou em uma diminuição na quantidade necessária para alcançar alta conversão mantendo a seletividade inalterada. A relação ligante/metal diminuiu de 100/1 (amina/Au) para 1/1 (fosfito/Au). A síntese de nanopartículas de ouro suportadas em carbono dopado com nitrogênio foi utilizada como método alternativo para a síntese de um catalisador heterogêneo de ouro ativo para hidrogenações seletivas. A principal vantagem em relação aos estudos anteriores foi evitar a adição de ligantes externos, em grande excesso, para a ativação de superfícies de ouro via FLP, tornando todo o processo ambiental e economicamente atraente

Catalysis , Catalyzer , Lewis Bases/antagonists & inhibitors , Gold/agonists , Ligands , Carbon/agonists , Health Strategies , Alkenes/classification , Metal Nanoparticles , Occupational Groups
Bol. malariol. salud ambient ; 62(5): 1048-1054, 2022. tab, graf
Article in Spanish | LILACS, LIVECS | ID: biblio-1428436


A medida que a se avanza en el siglo XXI, los sistemas de energía deben alejarse de los combustibles fósiles y aumentar la capacidad de las energías renovables si se quieren cumplir los objetivos de temperaturas máximas del Acuerdo de París. Sin embargo, debido a los desafíos en la adopción de tecnologías bajas en carbono, ciertas áreas de los sistemas energéticos globales son difíciles de controlar y descarburar. Por otra parte, el compostaje es una de las prácticas de gestión de residuos orgánicos más importantes que se puede utilizar para lograr la sostenibilidad del suelo y del medio ambiente. El compost tiene un mínimo impacto en algunas emisiones, y puede ayudar a controlar la huella de carbono y limitar los efectos ambientales negativos de los métodos de eliminación de desechos más deficientes. La investigación tuvo por objetivo determinar la calidad de producir biogás y biometano a partir de la cáscara de plátano (Musa paradisiaca L.). Metodológicamente se desarrolló una investigación aplicada, con nivel de investigación de tipo experimental. Las cáscaras de plátano se colectaron de la planta de compostaje de la Municipalidad Provincial de Leoncio Prado, Perú. De la muestra se prepararon cinco sub muestras para la producción de biogás y cinco muestras adicionales para la producción de biometano. Los sistemas mostraron una producción de 0,067 m3 BG/Kg ST de biogás y 0,059 m3CH4/Kg ST de biometano, que generó subproductos como el biol y biosol. Estos resultados presentaron una baja toxicidad al ser sometidos a pruebas germinativas, concluyéndose que solo el 11,5% de la cáscara introducida al biorreactor se degrado y de esta fracción solo el 2,8% se convirtió en biogás(AU)

As progress is being made in the 21st century, energy systems must move away from fossil fuels and increase the capacity of renewable energies if you want to meet the maximum temperatures objectives of the Paris Agreement. However, due to the challenges in the adoption of low carbon technologies, certain areas of global energy systems are difficult to control and decarbure. On the other hand, composting is one of the most important organic waste management practices that can be used to achieve soil and environmental sustainability. The compost has a minimum impact on some emissions, and can help control the carbon footprint and limit the negative environmental effects of the most deficient waste removal methods. The research aimed to determine the quality of producing biogas and biomethane from the banana peel (Musa paradisiaca L.). Methodologically, an applied investigation was developed, with experimental research level. The banana peels were collected from the composting plant of the Provincial Municipality of Leoncio Prado, Peru. From the sample, five sub samples were prepared for the production of biogas and five additional samples for biomethane production. The systems showed a production of 0.067 m3 bg/kg ST of biogas and 0.059 m3ch4/kg ST of biomethane, which generated by -products such as biol and biosol. These results presented a low toxicity when they were subjected to germinative evidence, concluding that only 11.5% of the shell introduced into the bioreactor was degraded and of this fraction only 2.8% became biogas(AU)

Conservation of Natural Resources/methods , Musa/metabolism , Biofuels/analysis , Carbon/analysis , Composting , Anaerobic Digestion , Musa/chemistry , Plant Bark/chemistry , Renewable Energy
Electron. j. biotechnol ; 52: 85-92, July. 2021. graf, tab
Article in English | LILACS | ID: biblio-1283600


BACKGROUND: Nonribosomal peptide synthases (NRPS) can synthesize functionally diverse bioactive peptides by incorporating nonproteinogenic amino acids, offering a rich source of new drug leads. The bacterium Escherichia coli is a well-characterized production host and a promising candidate for the synthesis of nonribosomal peptides, but only limited bioprocess engineering has been reported for such molecules. We therefore developed a medium and optimized process parameters using the design of experiments (DoE) approach. RESULTS: We found that glycerol is not suitable as a carbon source for rhabdopeptide production, at least for the NRPS used for this study. Alternative carbon sources from the tricarboxylic acid cycle achieved much higher yields. DoE was used to optimize the pH and temperature in a stirred-tank reactor, revealing that optimal growth and optimal production required substantially different conditions. CONCLUSIONS: We developed a chemically defined adapted M9 medium matching the performance of complex medium (lysogeny broth) in terms of product concentration. The maximum yield in the reactor under optimized conditions was 126 mg L-1, representing a 31-fold increase compared to the first shaking-flask experiments with M9 medium and glycerol as the carbon source. Conditions that promoted cell growth tended to inhibit NRPS productivity. The challenge was therefore to find a compromise between these factors as the basis for further process development.

Peptide Synthases/metabolism , Bioreactors/microbiology , Escherichia coli , Temperature , Biotechnology , Carbon/metabolism , Models, Statistical , Electrophoresis, Polyacrylamide Gel , Bioengineering , Hydrogen-Ion Concentration
Rev. chil. enferm. respir ; 37(1): 17-25, mar. 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1388129


INTRODUCCIÓN: En Chile, el funcionamiento de las Centrales Termoeléctricas de Carbón (CTEC) representan un problema de salud pública debido a las consecuencias sanitarias que tienen en la población. Se han notificado daños en el sistema respiratorio. Materiales y MÉTODOS: Se realizó un estudio ecológico, para evaluar los egresos hospitalarios de las personas que viven en las ciudades donde operan las CTEC (Tocopilla y Huasco), se comparó con una ciudad de control sin CTEC (Caldera), las comunas evaluadas tienen condiciones sociodemográficas similares. Se calcularon las tasas de morbilidad y tasas de morbilidad estandarizadas (SMR). RESULTADOS: La tasa de morbilidad por enfermedades respiratorias en Tocopilla (2016) fue de 152,5 por 10.000 habitantes (habs) y para Huasco es de 135,2 por 10.000 habs. En la ciudad control, Caldera, la tasa es de 40,9 por 10.000 habs. Además, los habitantes de Tocopilla tienen 2,42 más riesgo de padecer bronquitis o bronquiolitis, 90% más riesgo de presentar enfermedades crónicas de las vías respiratorias bajas y 2,14 veces más riesgo de enfermar por asma. En Huasco, la población tiene 2,49 veces más riesgo de padecer enfermedades de las vías respiratorias inferiores con respecto a la región y 3,19 veces más riesgo de presentar asma. CONCLUSIONES: El asma y la bronquitis, son las patologías que mostraron mayores riesgos en las ciudades de Tocopilla y Huasco. Nuestros hallazgos son similares a otras investigaciones realizadas en comunidades expuestas a centrales termoeléctricas de carbón. Es necesario tomar medidas urgentes para proteger la salud de la población.

INTRODUCTION: In Chile, coal-fired power plants (CTEC) operate represents public health problems due to the health consequences for the population. Damage to the respiratory system is reported. MATERIALS AND METHODS: Ecological study to evaluate hospital discharges in people living in cities where CTEC operates (Tocopilla and Huasco) were compared to a control city without CTEC (Caldera), all of them with similar sociodemographic conditions. Morbidity rates and Standardized Morbidity Ratios (SMR) were calculated. RESULTS: The respiratory disease morbidity rate in Tocopilla (2016) was 152.5 per 10,000 inhabitants (habs) and for Huasco it is 135.2 per 10,000 inhabitants. In the control city, Caldera, the rate is 40.9 per 10,000 habs. In addition, the inhabitants of Tocopilla have a 2.42 times increased risk of bronchitis or bronchiolitis, 90% higher risk of chronic lower respiratory diseases and 2.14 times more risk of asthma sickness. In Huasco, the population is 2.49 times more at risk of lower respiratory diseases compared to the region and 3.19 times more at risk of asthma. CONCLUSIONS: Asthma and bronchitis are the pathologies that showed the greatest risks in the cities of Tocopilla and Huasco. Our findings are similar to other research conducted in communities exposed to coal-fired power plants. Urgent action is needed to protect the health of the population.

Humans , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Power Plants , Respiratory Tract Diseases/epidemiology , Carbon , Environmental Pollutants/adverse effects , Patient Discharge/statistics & numerical data , Respiratory Tract Diseases/etiology , Chile/epidemiology , Risk , Age Distribution , Ecological Studies , Particulate Matter/adverse effects