318 research outputs found
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Integration of a Hydrogenase in a Lead Halide Perovskite Photoelectrode for Tandem Solar Water Splitting.
Lead halide perovskite solar cells are notoriously moisture-sensitive, but recent encapsulation strategies have demonstrated their potential application as photoelectrodes in aqueous solution. However, perovskite photoelectrodes rely on precious metal co-catalysts, and their combination with biological materials remains elusive in integrated devices. Here, we interface [NiFeSe] hydrogenase from Desulfovibrio vulgaris Hildenborough, a highly active enzyme for H2 generation, with a triple cation mixed halide perovskite. The perovskite-hydrogenase photoelectrode produces a photocurrent of -5 mA cm-2 at 0 V vs RHE during AM1.5G irradiation, is stable for 12 h and the hydrogenase exhibits a turnover number of 1.9 × 106. The positive onset potential of +0.8 V vs RHE allows its combination with a BiVO4 water oxidation photoanode to give a self-sustaining, bias-free photoelectrochemical tandem system for overall water splitting (solar-to-hydrogen efficiency of 1.1%). This work demonstrates the compatibility of immersed perovskite elements with biological catalysts to produce hybrid photoelectrodes with benchmark performance, which establishes their utility in semiartificial photosynthesis
Non-conductive silicon-containing materials improve methane production by pure cultures of methanogens
Supplementary data to this article can be found online at https://doi.org/10.1016/j.biortech.2024.131144.Conductive materials (CM) enhance methanogenesis, but there is no clear correlation between conductivity and faster methane production (MP) rates. We investigated if MP by pure cultures of methanogens (Methanobacterium formicicum, Methanospirillum hungatei, Methanothrix harundinacea and Methanosarcina barkeri) is affected by CM (activated carbon (AC), magnetite), and other sustainable alternatives (sand and glass beads, without conductivity, and zeolites (Zeo)). The significant impact of the materials was on M. formicicum as MP was significantly accelerated by non-CM (e.g., sand reduced the lag phase (LP) duration by 48 %), Zeo and AC (LP reduction in 71% and 75 %, respectively). Conductivity was not correlated with LP reduction. Instead, silicon content in the materials was inversely correlated with the time required for complete MP, and silicon per se stimulated M. formicicums activity. These findings highlight the potential of using non-CM silicon-containing materials in anaerobic digesters to accelerate methanogenesis.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the CM4Methane project (Ref: PTDC/BTA-BTA/2249/2021, DOI https://doi.org/10.54499/PTDC/BTA-BTA/2249/2021), the strategic funding of UIDB/04469/2020 unit, with DOI ttps://doi.org/10.54499/UIDB/04469/2020, and by LSRE-LCM, UIDB/50020/2020 (https://doi.org/10.54499/UIDB/50020/2020) and UIDP/50020/2020 (https://doi.org/10.54499/
UIDP/50020/2020). This research was also supported by BioEcoNorte project (NORTE-01-0145-FEDER-000070) funded by the European Regional Development Fund under the scope of Norte2020 – Programa
Operacional Regional do Norte. Catia S. N. Braga held SFRH/BD/132003/2017 and COVID/BD/152431/2022 grants funded by FCT and European Union, through the Portuguese State Budget and the European
Social Fund under the scope of Norte2020 – Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio
Transcriptional Response of Desulfovibrio vulgaris Hildenborough to Oxidative Stress Mimicking Environmental Conditions
Sulphate-reducing bacteria are anaerobes readily found in oxic-anoxic interfaces. Multiple defence pathways against oxidative conditions were identified in these organisms and proposed to be differentially expressed under different concentrations of oxygen, contributing to their ability to survive oxic conditions. In this study, Desulfovibrio vulgaris Hildenborough cells were exposed to the highest concentration of oxygen that sulphate-reducing bacteria are likely to encounter in natural habitats, and the global transcriptomic response was determined. 307 genes were responsive, with cellular roles in energy metabolism, protein fate, cell envelope and regulatory functions, including multiple genes encoding heat shock proteins, peptidases and proteins with heat shock promoters. Of the oxygen reducing mechanisms of D. vulgaris only the periplasmic hydrogen-dependent mechanism is up-regulated, involving the [NiFeSe]hydrogenase, formate dehydrogenase(s) and the Hmc membrane complex. The oxidative defence response concentrates on damage repair by metal-free enzymes. These data, together with the down regulation of the Fur operon, which restricts the availability of iron, and the lack of response of the PerR operon, suggest that a major effect of this oxygen stress is the inactivation and/or degradation of multiple metalloproteins present in D. vulgaris as a consequence of oxidative damage to their metal clusters
Combined tools for surgical case packages contents and cost optimization: a preliminary study
This paper presents a solution proposal based on mathematical and statistical tools to optimize Surgical Case Packages of an Operating Room (OR) in a Portuguese public hospital that it is the most complex environment in a hospital. In this particular hospital, more than 27000 surgeries/year are performed, employing, sometimes, misadjusted composition of standard surgical packages and non-optimized grouping of surgical instruments. Problem consequences are, among others, high transport of various surgical cases packages; high number of open cases and delays in surgical times following surgery. These type of problems are waste that do not add value to the service in the context of Lean Healthcare and must be eliminated using the most suitable tools. After the analysis, different tools were used: combinatorial analysis to optimize surgical cases composition and statistical analysis to identify the instruments usage and surgical basic case patterns. An optimization model was developed which produced a sterilizing initial solution of 135.24€. By identifying the most commonly employed instruments, it was concluded that some instruments have never been used and others rarely and some patterns were identified. The results achieved were based on minor sample and in a form of data collection that needs some adjustments.The authors want to acknowledge the Portuguese public hospital involved and to the ESGI initiative. The authors also would like to express their acknowledgments to national funds by COMPETE: POCI-01-0145-FEDER-007043 and FCT - Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio
Impact of organizational factors on accident prediction in the retail sector
Although different actions to prevent accidents at work have been implemented in companies, the number of accidents at work continues to be a problem for companies and society. In this way, companies have explored alternative solutions that have improved other business factors, such as predictive analysis, an approach that is relatively new when applied to occupational safety. Nevertheless, most reviewed studies focus on the accident dataset, i.e., the casualty’s characteristics, the accidents’ details, and the resulting consequences. This study aims to predict the occurrence of accidents in the following month through different classification algorithms of Machine Learning, namely, Decision Tree, Random Forest, Gradient Boost Model, K-nearest Neighbor, and Naive Bayes, using only organizational information, such as demographic data, absenteeism rates, action plans, and preventive safety actions. Several forecasting models were developed to achieve the best performance and accuracy of the models, based on algorithms with and without the original datasets, balanced for the minority class and balanced considering the majority class. It was concluded that only with some organizational information about the company can it predict the occurrence of accidents in the month ahead.USDA - U.S. Department of Agriculture(PCIF/GRF/0141/2019)The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020 and UIDP/05757/2020), ALGORITMI UIDB/00319/2020 and SusTEC (LA/P/0007/2021). This work has been supported by NORTE-01-0247-FEDER-072598 iSafety: Intelligent system for occupational safety and well-being in the retail sector. Inˆes Sena was supported by FCT PhD grant UI/BD/153348/2022
Cysteine Boosts Fitness Under Hypoxia-Mimicked Conditions in Ovarian Cancer by Metabolic Reprogramming
Funding Information: Funding. This research was supported by Funda??o para a Ci?ncia e Tecnologia (FCT) (Ph.D. ProRegeM program, Ref: PD/BD/105893/2014; FCT individual Ph.D. fellowship Ref: 2020.06956.BD) and iNOVA4 Health (Project 4 and Project 21). iNOVA4Health-UID/Multi/04462/2013 is a program financially supported by Funda??o para a Ci?ncia e Tecnologia/ Minist?rio da Educa??o e Ci?ncia, through national funds. The authors would like to acknowledge the Instituto Portugu?s de Oncologia de Lisboa Francisco Gentil (IPOLFG) for partially funding the project. Publisher Copyright: © Copyright © 2021 Nunes, Ramos, Santos, Mendes, Silva, Vicente, Pereira, Félix, Gonçalves and Serpa.Among gynecologic malignancies, ovarian cancer is the third most prevalent and the most common cause of death, especially due to diagnosis at an advanced stage together with resistance to therapy. As a solid tumor grows, cancer cells in the microenvironment are exposed to regions of hypoxia, a selective pressure prompting tumor progression and chemoresistance. We have previously shown that cysteine contributes to the adaptation to this hypoxic microenvironment, but the mechanisms by which cysteine protects ovarian cancer cells from hypoxia-induced death are still to be unveiled. Herein, we hypothesized that cysteine contribution relies on cellular metabolism reprogramming and energy production, being cysteine itself a metabolic source. Our results strongly supported a role of xCT symporter in energy production that requires cysteine metabolism instead of hydrogen sulfide (H2S) per se. Cysteine degradation depends on the action of the H2S-synthesizing enzymes cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and/or 3-mercaptopyruvate sulfurtransferase (MpST; together with cysteine aminotransferase, CAT). In normoxia, CBS and CSE inhibition had a mild impact on cysteine-sustained ATP production, pointing out the relevance of CAT + MpST pathway. However, in hypoxia, the concomitant inhibition of CBS and CSE had a stronger impact on ATP synthesis, thus also supporting a role of their hydrogen sulfide and/or cysteine persulfide-synthesizing activity in this stressful condition. However, the relative contributions of each of these enzymes (CBS/CSE/MpST) on cysteine-derived ATP synthesis under hypoxia remains unclear, due to the lack of specific inhibitors. Strikingly, NMR analysis strongly supported a role of cysteine in the whole cellular metabolism rewiring under hypoxia. Additionally, the use of cysteine to supply biosynthesis and bioenergetics was reinforced, bringing cysteine to the plateau of a main carbon sources in cancer. Collectively, this work supports that sulfur and carbon metabolism reprogramming underlies the adaptation to hypoxic microenvironment promoted by cysteine in ovarian cancer.publishersversionpublishe
Evaluation of parasite and host phenolic composition and bioactivities − The practical case of Cytinus hypocistis (L.) L. and Halimium lasianthum (Lam.) Greuter
Cytinus hypocistis (L.) L. is a comestible holoparasite with great potential for cosmeceutical application. Although its high tannin content has been associated with its bioactive and inhibitory enzyme properties, this is the first report establishing a relationship between parasite and host (Halimium lasianthum (Lam.) Greuter) phenolic profile and bioactive properties. Thus, five extracts (aerial and root extracts of non-parasited and parasited H. lasianthum and C. hypocistis) were evaluated. The tentative identification of both species comprises 39 phenolic compounds. Hydrolysable tannins and flavonoids were the main identified groups in C. hypocistis and H. lasianthum extracts, respectively. Regarding bioactivities, C. hypocistis exhibited excellent antioxidant results both in Oxidative Haemolysis (OxHLIA) and inhibition of Thiobarbituric Acid Reactive Substances Formation (TBARS). The tested extracts presented antimicrobial inhibition, anti-inflammatory activity, and effective cytotoxicity against tumour cells. C. hypocistis exhibited the lowest cytotoxicity on a non-tumour cell line. Principal Component Analysis (PCA) was a suitable approach to analyse differences among samples, explaining up to 67% of data variability and suggesting no similarities between parasite and host phenolic composition and bioactivities. Therefore, this comparative study emphasises the significance of both species as a source of biologically active compounds.The authors are grateful to the Foundation for Science and Technology
(FCT, Portugal) for financial support through national funds
FCT/MCTES to CIMO (UIDB/00690/2020). A. R. Silva is grateful to FCT
and FSE for her Doctoral Grant (SFRH/BD/145834/2019). L. Barros, C.
Pereira, I. Dias, and R. C. Calhelha are grateful to F.C.T. and P.I. for their
contracts through the institutional scientific employment programme.
The authors are also thankful to the FEDER-Interreg Espa˜na-Portugal
programme for financial support through the project TRANSCoLAB:
0612_TRANS_CO_LAB_2_P and to ERDF through the Regional Operational
Program North 2020, within the scope of the Project GreenHealth
- Norte-01–0145-FEDER-000042. This research was also funded by the
Serbian Ministry of Education, Science and Technological Development
(Contract No. 451–03-9/2021–14/200007).info:eu-repo/semantics/publishedVersio
[leptin As A Marker Of Sexual Dimorphism In Newborn Infants].
To determine cord blood leptin levels in newborns appropriate for gestational age, according to gender, birth weight, birth height and ponderal index. A cross-sectional study was carried out with 132 term newborns appropriate for gestational age (68 females, 64 males), gestational age between 35-42 weeks. Data were collected through interviews with the mothers at the maternity, anthropometrycal study of the newborns, and cord blood estradiol, testosterone and leptin assays obtained immediately after birth. The levels of leptin were significantly higher in females than in males (8.34+/-0.65 ng/ml versus 6.06+/-0.71 ng/ml; p = 0.000). The concentrations of estradiol and testosterone did not differ between males and females. Leptin levels were positively correlated with gestational age (r = 0.394, p < 0.01), birth weight (r = 0.466, p < 0.01), birth length (r = 0.335, p < 0.01) and ponderal index (r = 0.326, p < 0.01). Leptin concentration in the umbilical cord is positively correlated with gestational age, birth weight, birth height, and ponderal index, suggesting its participation in the neonatal growth process. In addition, a gender difference with higher levels of leptin in females neonates was observed, suggesting that the sexual dimorphism in relation to body composition already exists in newborns.80305-
Variability in chemical profile and bioactivities of the flesh of greek pumpkin landraces
The aim of this study was to evaluate the chemical profile of the flesh and yield parameters
of Greek pumpkin genotypes, including nine local landraces and two commercially available cultivars,
focusing on valorizing the genetic pool of Cucurbita sp. with high added value products. Yield
parameters (mean fruit weight and total fruit yield) recorded high variability with genotypes V8 and
V2 showing the highest fruit yield. Moreover, genotype V11 was the most abundant in glucose and
total sugars and scored the highest sweetness index suggesting good taste and promising marketing
attributes. The highest antioxidant activity (OxHLIA assay) was assessed in the V8 genotype, while
the V2 genotype showed the highest -, - and total tocopherols content. Oxalic acid was the main
organic acid, followed by malic and citric acids, while organic acid composition varied among the
tested genotypes. Moreover, the flesh extracts showed varied antimicrobial activity against several
bacteria and fungi, while no toxicity against non-tumor cells was recorded. In conclusion, our
results make evident the presence of high innate variability in terms of crop performance, chemical
composition and bioactive properties not only between the different genotypes but also at the intrapopulational
level. This finding is of high importance for the valorization of the local genetic pool
of Cucurbita species through the selection of elite genotypes with high yield and quality of fruit,
contributing to the conservation of valuable genetic material and limitation of the risk of genetic
erosion due to neglect of local landraces.This research was funded by the Foundation for Science and Technology (FCT), P.I. (FCT,
Portugal) through national funds FCT/MCTES to CIMO (UIDB/00690/2020 and UIDP/00690/2020),
SusTEC (LA/P/0007/2021) and UIDB/50006/2020. National funding by FCT, P.I., through the
institutional scientific employment program contract for M.I.D., R.C.C., C.P. and L.B. contracts, and
M.G. and A.K.M. PhD grants (2020.06706.BD and 2020.06231.BD, respectively); FCT, P.I., within the
scope of the Project PRIMA Section 2—Multi-topic 2019: PulpIng (PRIMA/0007/2019); the MICINN
for the Juan de la Cierva Formación contract for T.C.S.P.P. (FJC20120-045405-I); and the General
Secretariat for Research and Technology of the Ministry of Development and Investments under the
PRIMA Program. PRIMA is an Art.185 initiative supported and co-funded under Horizon 2020, the
European Union’s Program for Research and Plants 2022, 11, 800 16 of 18 Innovation (Prima2019-08).info:eu-repo/semantics/publishedVersio
Structural and spectroscopic characterization of a HdrA-like subunit from Hyphomicrobium denitrificans
Funding Information: We thank Laurenz Heidrich for help with statistical analyses. This work was supported by grant Da 351/8‐1 (to CD) from the Deutsche Forschungsgemeinschaft and Fundação para a Ciência e Tecnologia (Portugal) (grant PTDC/BIA‐BQM/29118 and R&D units MOSTMICRO‐ITQB (UIDB/04612/2020 and UIDP/04612/2020), and European Union's Horizon 2020 research and innovation program (grant agreement No 810856). Open access funding enabled and organized by Projekt DEAL. Publisher Copyright: © 2020 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Many bacteria and archaea employ a novel pathway of sulfur oxidation involving an enzyme complex that is related to the heterodisulfide reductase (Hdr or HdrABC) of methanogens. As a first step in the biochemical characterization of Hdr-like proteins from sulfur oxidizers (sHdr), we structurally analyzed the recombinant sHdrA protein from the Alphaproteobacterium Hyphomicrobium denitrificans at 1.4 Å resolution. The sHdrA core structure is similar to that of methanogenic HdrA (mHdrA) which binds the electron-bifurcating flavin adenine dinucleotide (FAD), the heart of the HdrABC-[NiFe]-hydrogenase catalyzed reaction. Each sHdrA homodimer carries two FADs and two [4Fe–4S] clusters being linked by electron conductivity. Redox titrations monitored by electron paramagnetic resonance and visible spectroscopy revealed a redox potential between −203 and −188 mV for the [4Fe–4S] center. The potentials for the FADH•/FADH− and FAD/FADH• pairs reside between −174 and −156 mV and between −81 and −19 mV, respectively. The resulting stable semiquinone FADH• species already detectable in the visible and electron paramagnetic resonance spectra of the as-isolated state of sHdrA is incompatible with basic principles of flavin-based electron bifurcation such that the sHdr complex does not apply this new mode of energy coupling. The inverted one-electron FAD redox potentials of sHdr and mHdr are clearly reflected in the different FAD-polypeptide interactions. According to this finding and the assumption that the sHdr complex forms an asymmetric HdrAA′B1C1B2C2 hexamer, we tentatively propose a mechanism that links protein-bound sulfane oxidation to sulfite on HdrB1 with NAD+ reduction via lipoamide disulfide reduction on HdrB2. The FAD of HdrA thereby serves as an electron storage unit. Database: Structural data are available in PDB database under the accession number 6TJR.publishe
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