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1.
Sci Total Environ ; 920: 170997, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38365022

RESUMO

Per- and Polyfluoroalkyl substances (PFAS) are a class of persistent chemicals, whose impact has been observed in various environmental compartments. Wastewater treatment plants (WWTPs) are considered a major emission pathway of PFAS, specifically in the context of the aquatic environment. The goal of this study was to develop a compartmentalized, source-based load estimation model of 7 PFAS within the municipal wastewater influent. Consumer statistics, data from literature on PFAS concentrations and release during use, and specific sampling activities for environmental flows in the related city were used to estimate per capita emission loads. Model results were compared with loads obtained through the monitoring campaign at the municipal WWTP influent. A wide range of discrepancies (≈5 % to ≈90 %) between loads observed in the WWTP influent and source based model estimates was noticed. The loads less accounted by the model were associated with sulfonic acids (PFSAs), whereas for carboxylic acids (PFCAs) most of the observed loads could be reasonably explained by the model, with even an overestimation of nearly 5 % noted for PFNA. Higher heterogeneity in sources was observed in the PFCA group, with a noticeable dominance in the share of consumer products. PFSAs had less of a consumer product input (<20 %), with the rest of the modelled load being attributed to environmental inputs. A large gap of unknown loads of PFSAs indicates a need for examination of other, not yet quantified activities that can potentially explain the remainder of the observed load. Especially commercial activities are considered as potential additional sources for PFSAs. These findings signify the importance of PFAS that originate from both consumer products, as well as environmental inputs in the overall load contribution into the sewage, while identifying the need for further investigation into commercial sources of PFAS emitted into the municipal wastewater.

2.
Environ Sci Technol ; 58(2): 971-990, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38166114

RESUMO

Global resource extraction raises concerns about environmental pressures and the security of mineral supply. Strategies to address these concerns depend on robust information on natural resource endowments, and on suitable methods to monitor and model their changes over time. However, current mineral resources and reserves reporting and accounting workflows are poorly suited for addressing mineral depletion or answering questions about the long-term sustainable supply. Our integrative review finds that the lack of a robust theoretical concept and framework for mass-balance (MB)-consistent geological stock accounting hinders systematic industry-government data integration, resource governance, and strategy development. We evaluate the existing literature on geological stock accounting, identify shortcomings of current monitoring of mine production, and outline a conceptual framework for MB-consistent system integration based on material flow analysis (MFA). Our synthesis shows that recent developments in Earth observation, geoinformation management, and sustainability reporting act as catalysts that make MB-consistent geological stock accounting increasingly feasible. We propose first steps for its implementation and anticipate that our perspective as "resource realists" will facilitate the integration of geological and anthropogenic material systems, help secure future mineral supply, and support the global sustainability transition.


Assuntos
Conservação dos Recursos Naturais , Minerais , Conservação dos Recursos Naturais/métodos
3.
J Gen Appl Microbiol ; 69(4): 185-195, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36935115

RESUMO

Although n-butanol (BuOH) is an ideal fuel because of its superior physical properties, it has toxicity to microbes. Previously, a Synechococcus elongatus PCC 7942 derivative strain that produces BuOH from CO2 was developed by introducing six heterologous genes (BUOH-SE strain). To identify the bottleneck in BuOH production, the effects of BuOH production and its toxicity on central metabolism and the photosystem were investigated. Parental (WT) and BUOH-SE strains were cultured under autotrophic conditions. Consistent with the results of a previous study, BuOH production was observed only in the BUOH-SE strain. Isotopically non-stationary 13C-metabolic flux analysis revealed that the CO2 fixation rate was much larger than the BuOH production rate in the BUOH-SE strain (1.70 vs 0.03 mmol gDCW-1 h-1), implying that the carbon flow for BuOH biosynthesis was less affected by the entire flux distribution. No large difference was observed in the flux of metabolism between the WT and BUOH-SE strains. Contrastingly, in the photosystem, the chlorophyll content and maximum O2 evolution rate per dry cell weight of the BUOH-SE strain were decreased to 81% and 43% of the WT strain, respectively. Target proteome analysis revealed that the amounts of some proteins related to antennae (ApcA, ApcD, ApcE, and CpcC), photosystem II (PsbB, PsbU, and Psb28-2), and cytochrome b6f complex (PetB and PetC) in photosystems decreased in the BUOH-SE strain. The activation of photosynthesis would be a novel approach for further enhancing BuOH production in S. elongatus PCC 7942.


Assuntos
1-Butanol , Proteoma , Proteoma/genética , Complexo Citocromos b6f , Dióxido de Carbono , Fotossíntese , Butanóis
4.
Front Plant Sci ; 14: 1140829, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38078077

RESUMO

Introduction: Flux phenotypes from different organisms and growth conditions allow better understanding of differential metabolic networks functions. Fluxes of metabolic reactions represent the integrated outcome of transcription, translation, and post-translational modifications, and directly affect growth and fitness. However, fluxes of intracellular metabolic reactions cannot be directly measured, but are estimated via metabolic flux analysis (MFA) that integrates data on isotope labeling patterns of metabolites with metabolic models. While the application of metabolomics technologies in photosynthetic organisms have resulted in unprecedented data from 13CO2-labeling experiments, the bottleneck in flux estimation remains the application of isotopically nonstationary MFA (INST-MFA). INST-MFA entails fitting a (large) system of coupled ordinary differential equations, with metabolite pools and reaction fluxes as parameters. Here, we focus on the Calvin-Benson cycle (CBC) as a key pathway for carbon fixation in photosynthesizing organisms and ask if approaches other than classical INST-MFA can provide reliable estimation of fluxes for reactions comprising this pathway. Methods: First, we show that flux estimation with the labeling patterns of all CBC intermediates can be formulated as a single constrained regression problem, avoiding the need for repeated simulation of time-resolved labeling patterns. Results: We then compare the flux estimates of the simulation-free constrained regression approach with those obtained from the classical INST-MFA based on labeling patterns of metabolites from the microalgae Chlamydomonas reinhardtii, Chlorella sorokiniana and Chlorella ohadii under different growth conditions. Discussion: Our findings indicate that, in data-rich scenarios, simulation-free regression-based approaches provide a suitable alternative for flux estimation from classical INST-MFA since we observe a high qualitative agreement (rs=0.89) to predictions obtained from INCA, a state-of-the-art tool for INST-MFA.

5.
Waste Manag ; 171: 218-226, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37666147

RESUMO

Driven by European legislation, counties must improve their plastic packaging recycling system to meet ambitious recycling targets. This study analyses the current plastic packaging recycling system in Norway, together with three alternative systems and evaluates their performance on environmental impact and achievement of policy indicators. The alternative systems include measures to increase separation of plastic packaging waste and to increase plastic sorting capacity in Norway. A lower impact on climate change (between 531 kg and 874 kg CO2 eq. compared to the current system) was obtained for scenarios with high separation of plastic packaging waste. Without better waste separation, increased sorting in Norway resulted in a higher impact on climate change (between 46 kg and 123 kg CO2 eq.) compared to the current system. Mixed-waste MRFs can help to obtain high recycling rates, but their implementation should be coordinated centrally to avoid potential adverse effects. Furthermore, none of the proposed systems reached the recycling rate targets, showing that improvements are necessary across the entire value chain.

6.
Sci Total Environ ; 904: 167248, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37739081

RESUMO

Palladium (Pd) is a strategic metal and can help reduce environmental pollution, especially from vehicle exhausts. China is the world's largest Pd consumer, but with very limited reserves. However, Pd anthropogenic cycles remain unclear in China. This study aims to uncover the dynamic Pd flows and stocks in China for the period of 2001-2020 by conducting dynamic material flow analysis. The results show that the demand for Pd had increased by 10 folds during the study period due to stricter vehicle emissions policies. Also, China mainly imported such resource from the United States, Western Europe, and East Asia, with a share of 88.8 %. However, due to insufficient end-of-life vehicle (ELV) recycling system, the total recycled Pd was only 12.3 tons although the end-of-life Pd flow increased from 3.7 tons in 2001 to 30.8 tons in 2020. This implies a great Pd recycling potential. Therefore, it is urgent to promote Pd recycling by establishing an effective Pd recycling system. In addition, other policy recommendations, such as diversifying Pd import partners, increasing Pd emergency reserves, and economic instruments, are raised by considering the Chinese realities so that the overall Pd resource efficiency can be improved.

7.
Sci Total Environ ; 904: 166368, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37619721

RESUMO

Clean technologies are rapidly increasing in the last decade. In the transport sector, market share of global electric car sales has changed from 0.0 % in 2010 to 3.2 % (2.1million) in 2020, and predictions show that sales could reach near 30 % in 2030. This drastic change is mainly encouraged by environmental goals set to reduce greenhouse gas emissions (GHG) expressed in CO2-eq, not emitted by electric vehicles (EVs) during the use phase. However, clean technologies might cause other impacts during manufacture and, while clearly reduce the dependency on oil, can increase the dependency on other materials. In this context, the objectives of our work are quantifying the critical raw materials needed by permanents magnets and batteries of EVs (neodymium, lithium, and cobalt); their supply risk, performing a material flow analysis; and studying their environmental impacts using the methodology "Environmentally-Extended Multi-Regional Input-Output Analysis". This methodology is used to quantify the produced impacts and the country where the impacts are being produced, in contrast to conventional methodologies that only calculate global impacts. Therefore, environmental impacts are estimated considering different scenarios, based on environmental objectives of the European Union and China. In most scenarios China shows a key role in mining and processing of metals, being the country where major impacts are produced. Obtained results are useful to assess which environmental proposals are more effective to reduce the environmental impact of EVs and set the ground to understand the geostrategic importance of key metals used for EVs manufacture.

8.
Cell Rep ; 42(8): 112971, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37578864

RESUMO

Fatty acid synthase (FASN) maintains de novo lipogenesis (DNL) to support rapid growth in most proliferating cancer cells. Lipogenic acetyl-coenzyme A (CoA) is primarily produced from carbohydrates but can arise from glutamine-dependent reductive carboxylation. Here, we show that reductive carboxylation also occurs in the absence of DNL. In FASN-deficient cells, reductive carboxylation is mainly catalyzed by isocitrate dehydrogenase-1 (IDH1), but IDH1-generated cytosolic citrate is not utilized for supplying DNL. Metabolic flux analysis (MFA) shows that FASN deficiency induces a net cytosol-to-mitochondria citrate flux through mitochondrial citrate transport protein (CTP). Previously, a similar pathway has been shown to mitigate detachment-induced oxidative stress in anchorage-independent tumor spheroids. We further report that tumor spheroids show reduced FASN activity and that FASN-deficient cells acquire resistance to oxidative stress in a CTP- and IDH1-dependent manner. Collectively, these data indicate that by inducing a cytosol-to-mitochondria citrate flux, anchorage-independent malignant cells can gain redox capacity by trading off FASN-supported rapid growth.


Assuntos
Ácido Cítrico , Isocitrato Desidrogenase , Ácido Cítrico/metabolismo , Citosol/metabolismo , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Linhagem Celular Tumoral , Citratos/metabolismo , Estresse Oxidativo , Óxido Nítrico Sintase/metabolismo , Ácido Graxo Sintases/metabolismo , Mitocôndrias/metabolismo , Lipogênese
9.
Sci Total Environ ; 900: 165855, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37516171

RESUMO

Studies on the occurrence and fates of emerging organic micropollutants (EOMPs) like pharmaceuticals and pesticides in MSWs are scarce in the literature. Therefore, MSWs were sampled from 20 Indian landfills and characterized for five widely consumed EOMPs (chlorpyrifos, cypermethrin, carbofuran, carbamazepine, and sodium diclofenac), physicochemical, and biological properties. The pesticide (median: 0.17-0.44 mg kg-1) and pharmaceutical (median: 0.20-0.26 mg kg-1) concentrations significantly fluctuated based on landfill localities. Eventually, principal component and multi-factor (MFA) models demonstrated close interactions of EOMPs with biological (microbial biomass and humification rates) and chemical (N, P, K, Ca, S, etc.) properties of MSWs. At the same time, the MFA resolved that EOMPs' fates in MSWs significantly differ from bigger cosmopolitan cities to smaller rural townships. Correspondingly, the concentration-driven ecological risks were high in 15 MSWs with EOMP-toxicity ranks of diclofenac > carbofuran = chlorpyrifos > cypermethrin > carbamazepine. The EOMPs' dissolution dynamics and source apportionments were evaluated using the positive matrix factorization (PMF) model for the first time on experimental data, extracting four anthropogenic sources (households, heterogeneous business centers, agricultural, and open drains). The most significant contribution of EOMPs to MSWs was due to heterogeneous business activity. Notably, the aging of soluble chemical fractions seems to influence the source characteristics of EOMPs strongly.


Assuntos
Carbofurano , Clorpirifos , Praguicidas , Resíduos Sólidos/análise , Praguicidas/análise , Solubilidade , Medição de Risco , Carbamazepina/análise , Preparações Farmacêuticas
10.
J Environ Manage ; 344: 118461, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37481914

RESUMO

Increasing aluminum demand under the clean energy and low-carbon transformation background increases the fuzziness of relationships between economic growth and aluminum use or aluminum related carbon emissions. To figure this out, this paper established an aluminum use and carbon emissions integrated decoupling model within the framework of anthropogenic aluminum cycle. A material flow analysis (MFA) during 2000-2020 for China's aluminum cycle was firstly conducted to quantify both aluminum flow and carbon emissions in each aluminum life-cycle process. Then, this paper evaluated and decomposed the decoupling index of aluminum use-economy and carbon emission-economy via the LMDI decomposition model. Results show that: (1) secondary aluminum has not become effective supplement for primary aluminum in China; (2) the expansive negative decoupling state was the most prevalent state. The decoupling effects of carbon emission were better than that of aluminum use; (3) technology improvement was an important impactor to decoupling process but didn't offset the growth in aluminum consumption or carbon emissions at most of the time. The government and industry organizers should implement active countermeasures to stimulate aluminum companies developing technology to improve aluminum use efficiency and reduce carbon emissions.


Assuntos
Carbono , Desenvolvimento Econômico , Carbono/análise , Alumínio , Dióxido de Carbono/análise , China
11.
Blood Cells Mol Dis ; 102: 102760, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37267696

RESUMO

Hematopoiesis and lineage commitment are regulated by several conserved cell-intrinsic signaling pathways, including MAPKs and ß-catenin/TCF/LEF. The Inhibitor of MyoD Family A (I-MFA), a transcriptional repressor and tumor suppressor gene, interacts with these pathways and is dysregulated in chronic and acute myeloid leukemias, suggesting it may play a role in development and differentiation during hematopoiesis. To study this, immune cell populations in the bone marrow (BM) and periphery were analyzed in mice lacking Mdfi, encoding I-MFA (I-MFA-/-), and wild type (WT) controls. I-MFA-/- mice had reduced spleen and BM cellularity, with significant hyposplenism, compared to WT mice. In blood, total red blood cells and platelet counts were significantly reduced in I-MFA-/- mice, accompanied by a reduction in megakaryocyte (MK)/erythrocyte progenitor cells and an increase in myeloid progenitors in BM compared to WT mice. The K562 cell line exhibits PMA-induced MK differentiation, and shRNA knockdown of I-MFA resulted in reduced differentiation compared to control, with an increase and prolongation in phospho-JNK and phospho-ERK signaling. Overexpression of I-MFA promoted MK differentiation. These results suggest I-MFA plays a cell-intrinsic role in the response to differentiation signals, an effect that can be explored in the context of hematological cancers or other blood proliferative disorders.


Assuntos
Medula Óssea , Megacariócitos , Camundongos , Animais , Medula Óssea/metabolismo , Diferenciação Celular , Hematopoese , Células da Medula Óssea/patologia , Linhagem da Célula
12.
Front Cell Infect Microbiol ; 13: 1146030, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37305421

RESUMO

Some parasitic diseases, such as malaria, require two hosts to complete their lifecycle: a human and an insect vector. Although most malaria research has focused on parasite development in the human host, the life cycle within the vector is critical for the propagation of the disease. The mosquito stage of the Plasmodium lifecycle represents a major demographic bottleneck, crucial for transmission blocking strategies. Furthermore, it is in the vector, where sexual recombination occurs generating "de novo" genetic diversity, which can favor the spread of drug resistance and hinder effective vaccine development. However, understanding of vector-parasite interactions is hampered by the lack of experimental systems that mimic the natural environment while allowing to control and standardize the complexity of the interactions. The breakthrough in stem cell technologies has provided new insights into human-pathogen interactions, but these advances have not been translated into insect models. Here, we review in vivo and in vitro systems that have been used so far to study malaria in the mosquito. We also highlight the relevance of single-cell technologies to progress understanding of these interactions with higher resolution and depth. Finally, we emphasize the necessity to develop robust and accessible ex vivo systems (tissues and organs) to enable investigation of the molecular mechanisms of parasite-vector interactions providing new targets for malaria control.


Assuntos
Culicidae , Malária , Humanos , Animais , Mosquitos Vetores , Meio Ambiente , Tecnologia
13.
Plant Methods ; 19(1): 58, 2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37328911

RESUMO

BACKGROUND: To gain a better understanding of bark layer structure and function, especially of the phloem fibres and their contribution to the posture control of trees, it is important to map the structural properties of these cells. The role of bark can also be linked to the reaction wood formation and properties which are essential when it comes to studying the questions related to tree growth. To offer new insights into the role of bark in the postural control of trees, we studied the micro- and nanoscale structures of the phloem and its nearest layers. This study is the first time, in which phloem fibres in trees have been extensively examined using X-ray diffraction (XRD). We determined the orientation of cellulose microfibrils in phloem fibres of Silver birch saplings by using scanning synchrotron nanodiffraction. The samples consisted of phloem fibres extracted from tension, opposite and normal wood (TW, OW, NW). RESULTS: Using scanning XRD, we were able to obtain new information about the mean microfibril angle (MFA) in cellulose microfibrils in phloem fibres connected to reaction wood. A slight but consistent difference was detected in the average MFA values of phloem fibres between the TW and OW sides of the stem. Using scanning XRD, different contrast agents (intensity of the main cellulose reflection or calcium oxalate reflection, mean MFA value) were used to produce 2D images with 200 nm spatial resolution. CONCLUSIONS: Based on our results, the tension wood formation in the stem might be related to the structure and properties of phloem fibres. Thus, our results suggest that the nanostructure of phloem fibres is involved in the postural control of trees containing tension and opposite wood.

14.
Environ Dev Sustain ; : 1-23, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-37362969

RESUMO

As highly concentrated urbanized areas, urban agglomerations bear increasing resource depletion and environmental pressures, which threaten the regional sustainable development. Resource and environmental problems arising from the process of urbanization can be attributed to the dislocation or maladjustment of material metabolism in time or space. Conducting research on material metabolism at the level of urban agglomerations is helpful in finding the root causes of environmental problems to provide support for the reduction of regional resource consumption and pollution emissions. The material metabolism characteristics of the urban agglomeration and internal cities of the Fujian Delta Urban Agglomeration (FDUA) in China are evaluated using the material flow analysis. The following results are observed. (1) The economic development of the FDUA is still at risk of resource consumption, and a large proportion of hidden flow (HF > 80%) drags down the overall metabolic efficiency and sustainable development. (2) The discharge of various pollutants in the FDUA generally shows a downward trend. Improving metabolic efficiency, delayed MCI growth, and improved overall regional environmental quality are observed. (3) Cities that have relatively scarce land resources but are economically developed, such as Xiamen, still bear a relatively heavy ecological burden (ECdmc > 1). (4) Regional collaboration is conducive to the sustainable development of multiple regions. On the one hand, the results of this study provide decision-making basis for the sustainable development of the national ecological civilization demonstration area. On the other hand, this work guides the establishment of a comprehensive industrial linkage and cooperation mechanism for the same type of small- and medium-sized urban agglomerations.

15.
Digit Health ; 9: 20552076231177144, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37252257

RESUMO

Objective: This review paper aims to evaluate existing solutions in healthcare authentication and provides an insight into the technologies incorporated in Internet of Healthcare Things (IoHT) and multi-factor authentication (MFA) applications for next-generation authentication practices. Our review has two objectives: (a) Review MFA based on the challenges, impact and solutions discussed in the literature; and (b) define the security requirements of the IoHT as an approach to adapting MFA solutions in a healthcare context. Methods: To review the existing literature, we indexed articles from the IEEE Xplore, ACM Digital Library, ScienceDirect, and SpringerLink databases. The search was refined to combinations of 'authentication', 'multi-factor authentication', 'Internet of Things authentication', and 'medical authentication' to ensure that the retrieved journal articles and conference papers were relevant to healthcare and Internet of Things-oriented authentication research. Results: The concepts of MFA can be applied to healthcare where security can often be overlooked. The security requirements identified result in stronger methodologies of authentication such as hardware solutions in combination with biometric data to enhance MFA approaches. We identify the key vulnerabilities of weaker approaches to security such as password use against various cyber threats. Cyber threats and MFA solutions are categorised in this paper to facilitate readers' understanding of them in healthcare domains. Conclusions: We contribute to an understanding of up-to-date MFA approaches and how they can be improved for use in the IoHT. This is achieved by discussing the challenges, benefits, and limitations of current methodologies and recommendations to improve access to eHealth resources through additional layers of security.

16.
J Oral Microbiol ; 15(1): 2215551, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37223052

RESUMO

Background: Mfa1 fimbriae of the periodontal pathogen Porphyromonas gingivalis are responsible for biofilm formation and comprise five proteins: Mfa1-5. Two major genotypes, mfa170 and mfa153, encode major fimbrillin. The mfa170 genotype is further divided into the mfa170A and mfa170B subtypes. The properties of the novel mfa170B remain unclear. Methods: Fimbriae were purified from P. gingivalis strains JI-1 (mfa170A), 1439 (mfa170B), and Ando (mfa153), and their components and their structures were analyzed. Protein expression and variability in the antigenic specificity of fimbrillins were compared using Coomassie staining and western blotting using polyclonal antibodies against Mfa170A, Mfa170B, and Mfa153 proteins. Cell surface expression levels of fimbriae were analyzed by filtration enzyme-linked immunosorbent assays. Results: The composition and structures of the purified Mfa1 fimbriae of 1439 was similar to that of JI-1. However, each Mfa1 protein of differential subtype/genotype was specifically detected by western blotting. Mfa170B fimbriae were expressed in several strains such as 1439, JKG9, B42, 1436, and Kyudai-3. Differential protein expression and antigenic heterogeneities were detected in Mfa2-5 between strains. Conclusion: Mfa1 fimbriae from the mfa170A and mfa170B genotypes indicated an antigenic difference suggesting the mfa170B, is to be utilized for the novel classification of P. gingivalis.

17.
Metab Eng ; 77: 231-241, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37024071

RESUMO

To investigate the metabolic elasticity and production bottlenecks for recombinant silk proteins in Escherichia coli, we performed a comprehensive characterization of one elastin-like peptide strain (ELP) and two silk protein strains (A5 4mer, A5 16mer). Our approach included 13C metabolic flux analysis, genome-scale modeling, transcription analysis, and 13C-assisted media optimization experiments. Three engineered strains maintained their central flux network during growth, while measurable metabolic flux redistributions (such as the Entner-Doudoroff pathway) were detected. Under metabolic burdens, the reduced TCA fluxes forced the engineered strain to rely more on substrate-level phosphorylation for ATP production, which increased acetate overflow. Acetate (as low as 10 mM) in the media was highly toxic to silk-producing strains, which reduced 4mer production by 43% and 16mer by 84%, respectively. Due to the high toxicity of large-size silk proteins, 16mer's productivity was limited, particularly in the minimal medium. Therefore, metabolic burden, overflow acetate, and toxicity of silk proteins may form a vicious positive feedback loop that fractures the metabolic network. Three solutions could be applied: 1) addition of building block supplements (i.e., eight key amino acids: His, Ile, Phe, Pro, Tyr, Lys, Met, Glu) to reduce metabolic burden; 2) disengagement of growth and production; and 3) use of non-glucose based substrate to reduce acetate overflow. Other reported strategies were also discussed in light of decoupling this positive feedback loop.


Assuntos
Escherichia coli , Fibroínas , Escherichia coli/metabolismo , Fibroínas/genética , Fibroínas/metabolismo , Retroalimentação , Redes e Vias Metabólicas , Proteínas Recombinantes/metabolismo , Acetatos/metabolismo
18.
Sensors (Basel) ; 23(5)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36904955

RESUMO

The overwhelming popularity of technology-based solutions and innovations to address day-to-day processes has significantly contributed to the emergence of smart cities. where millions of interconnected devices and sensors generate and share huge volumes of data. The easy and high availability of rich personal and public data generated in these digitalized and automated ecosystems renders smart cities vulnerable to intrinsic and extrinsic security breaches. Today, with fast-developing technologies, the classical username and password approaches are no longer adequate to secure valuable data and information from cyberattacks. Multi-factor authentication (MFA) can provide an effective solution to minimize the security challenges associated with legacy single-factor authentication systems (both online and offline). This paper identifies and discusses the role and need of MFA for securing the smart city ecosystem. The paper begins by describing the notion of smart cities and the associated security threats and privacy issues. The paper further provides a detailed description of how MFA can be used for securing various smart city entities and services. A new concept of blockchain-based multi-factor authentication named "BAuth-ZKP" for securing smart city transactions is presented in the paper. The concept focuses on developing smart contracts between the participating entities within the smart city and performing the transactions with zero knowledge proof (ZKP)-based authentication in a secure and privacy-preserved manner. Finally, the future prospects, developments, and scope of using MFA in smart city ecosystem are discussed.

19.
Microorganisms ; 11(2)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36838259

RESUMO

Inorganic pyrophosphatases (PPases) catalyze an essential reaction, namely, the hydrolysis of PPi, which is formed in large quantities as a side product of numerous cellular reactions. In the majority of living species, PPi hydrolysis is carried out by soluble cytoplasmic PPase (S-PPases) with the released energy dissipated in the form of heat. In Rhodospirillum rubrum, part of this energy can be conserved by proton-pumping pyrophosphatase (H+-PPaseRru) in the form of a proton electrochemical gradient for further ATP synthesis. Here, the codon-harmonized gene hppaRru encoding H+-PPaseRru was expressed in the Escherichia coli chromosome. We demonstrate, for the first time, that H+-PPaseRru complements the essential native S-PPase in E. coli cells. 13C-MFA confirmed that replacing native PPase to H+-PPaseRru leads to the re-distribution of carbon fluxes; a statistically significant 36% decrease in tricarboxylic acid (TCA) cycle fluxes was found compared with wild-type E. coli MG1655. Such a flux re-distribution can indicate the presence of an additional method for energy generation (e.g., ATP), which can be useful for the microbiological production of a number of compounds, the biosynthesis of which requires the consumption of ATP.

20.
Toxicon X ; 17: 100150, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36747993

RESUMO

This paper reviews toxic plants for livestock in South America. We included 219 plants in this review, considering only the plants that caused at least one demonstrated outbreak of poisoning. Plants reported as toxic in other regions and present in South America, but with no confirmed outbreaks of poisoning in this region, are not included. We report the main aspects of the epidemiology, clinical signs, pathology and economical importance of the poisonings. Initially, the toxic plants are described based on their toxic compounds, but because the toxic compound is unknown in 92 (42%) of the plants we also classify them according to the affected system. This review highlights the great diversity of toxic plants capable of affecting livestock in South America, and for this reason studies in this regard should be intensified.

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