Transcription profiles of hydrogenases related genes in the cyanobacterium Lyngbya majuscula CCAP 1446/4

<p>Abstract</p> <p>Background</p> <p><it>Lyngbya majuscula </it>CCAP 1446/4 is a N₂-fixing filamentous nonheterocystous strain that contains two NiFe-hydrogenases: an uptake (encoded by <it>hupSL</it>) and a bidirectional enzyme (encoded by <it>hoxEFUYH</it>). The biosynthesis/maturation of NiFe-hydrogenases is a complex process requiring several accessory proteins for e.g. for the incorporation of metals and ligands in the active center (large subunit), and the insertion of the FeS clusters (small subunit). The last step in the maturation of the large subunit is the cleavage of a C-terminal peptide from its precursor by a specific endopeptidase. Subsequently, the mature large and small subunits can assemble forming a functional enzyme.</p> <p>Results</p> <p>In this work we demonstrated that, in <it>L. majuscula</it>, the structural genes encoding the bidirectional hydrogenase are cotranscribed, and that <it>hoxW </it>(the gene encoding its putative specific endopeptidase) is in the same chromosomal region but transcribed from a different promoter. The gene encoding the putative specific uptake hydrogenase endopeptidase, <it>hupW</it>, can be cotranscribed with the structural genes but it has its own promoter. <it>hoxH</it>, <it>hupL</it>, <it>hoxW </it>and <it>hupW </it>transcription was followed in <it>L. majuscula </it>cells grown under N₂-fixing and non-N₂-fixing conditions over a 12 h light/12 h dark cycle. The transcription of <it>hoxH</it>, <it>hoxW </it>and <it>hupW </it>did not vary remarkably in the conditions tested, while the <it>hupL </it>transcript levels are significantly higher under N₂-fixing conditions with a peak occurring in the transition between the light and the dark phase. Furthermore, the putative endopeptidases transcript levels, in particular <it>hoxW</it>, are lower than those of the respective hydrogenase structural genes.</p> <p>Conclusion</p> <p>The data presented here indicate that in <it>L. majuscula </it>the genes encoding the putative hydrogenases specific endopeptidases, <it>hoxW </it>and <it>hupW</it>, are transcribed from their own promoters. Their transcript levels do not vary notably in the conditions tested, suggesting that HoxW and HupW are probably constantly present and available in the cells. These results, together with the fact that the putative endopeptidases transcript levels, in particular for <it>hoxW</it>, are lower than those of the structural genes, imply that the activity of the hydrogenases is mainly correlated to the transcription levels of the structural genes. The analysis of the promoter regions indicates that <it>hupL </it>and <it>hupW </it>might be under the control of different transcription factor(s), while both <it>hoxH </it>and <it>xisH </it>(<it>hoxW</it>) promoters could be under the control of LexA.</p

A confrontação entre Heidegger e Nietzsche no âmbito da estética

O presente trabalho tem por objetivo analisar os principais pontos da “confrontação” (assim chamada por Heidegger) entre Heidegger e Nietzsche, tendo por foco a questão da estética e sua concomitância com a metafísica. É por esta via que pretenderemos elucidar a permanência de Nietzsche no campo da metafísica como seu último pensador.This paper aims to analyze the main points of the "confrontation" (so called by Heidegger) between Heidegger and Nietzsche, with the focus on the issue aesthetics and its concomitant with metaphysics. It is by this means that we will intend to elucidate the persistence of Nietzsche in the field of metaphysics as its last thinker

Polypeptides and proteins that influence beer foam quality and analytical methods used in their study

POLYPEPTIDES AND PROTEINS THAT INFLUENCE BEER FOAM QUALITY AND ANALYTICAL METHODS USED IN THEIR STUDY A review of polypeptides and proteins that influence, direct or indirectly, beer foam quality, as well as the most relevant analytical methods used in their study, are presented. Protein Z, LTP1 and hordein/glutelin fragments originated from malt have a direct influence on beer foam quality. Other proteins, like malt hordeins and albumins and wheat puroindolines, are, to some degree, also important for beer foam quality. Protein hydrophobicity is pointed out as a key parameter to enhance foam quality. Electrophoretic, chromatographic and immunological analytical methods are currently used to study polypeptides and proteins present in barley, malt, wort, beer, and foam. Best results are obtained when combinations of these methods are applied

Anomalous Nernst Effect in flexible co-based amorphous ribbons

Fe3Co67Cr3Si15B12 ribbons with a high degree of flexibility and excellent corrosion stability were produced by rapid quenching technique. Their structural, magnetic, and thermomagnetic (Anomalous Nernst Effect) properties were studied both in an as-quenched (NR) state and after stress annealing during 1 h at the temperature of 350 °C and a specific load of 230 MPa (AR). X-ray diffraction was used to verify the structural characteristics of our ribbons. Static magnetic properties were explored by inductive technique and vibrating sample magnetometry. The thermomagnetic curves investigated through the Anomalous Nernst Effect are consistent with the obtained magnetization results, presenting a linear response in the thermomagnetic signal, an interesting feature for sensor applications. Additionally, Anomalous Nernst Effect coefficient SANE values of 2.66μV/K and 1.93μV/K were estimated for the as-quenched and annealed ribbons, respectively. The interplay of the low magnetostrictive properties, soft magnetic behavior, linearity of the thermomagnetic response, and flexibility of these ribbons place them as promising systems to probe curved surfaces and propose multifunctional devices, including magnetic field-specialized sensors.M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18- C.F. (2) junior researcher contract). G.V.K was supported in the frame of the Priority-2030 Program of Ural Federal University

Longitudinal Spin Seebeck Effect thermopiles based on flexible Co-rich amorphous ribbons/Pt thin-film heterostructures

Thermoelectric phenomena, such as the Anomalous Nernst and Longitudinal Spin Seebeck Effects, are promising for sensor applications in the area of renewable energy. In the case of flexible electronic materials, the request is even larger because they can be integrated into devices having complex shape surfaces. Here, we reveal that Pt promotes an enhancement of the thermoelectric response in Co-rich ribbon/Pt heterostructures due to the spin-to-charge conversion. Moreover, we demonstrated that the employment of the thermopiles configuration in this system increases the induced thermoelectric current, a fact related to the considerable decrease in the electric resistance of the system. By comparing present findings with the literature, we were able to design a flexible thermopile based on LSSE without the lithography process. Additionally, the thermoelectric voltage found in the studied flexible heterostructures is comparable to the ones verified for rigid systems.This research was funded by different sources. M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18-C.F. (2) junior researcher contract). A.V.S. and G.V.K. were supported in the frame of the Priority-2030 Program of Ural Federal University

Reabilitação Cardíaca Após Síndrome Coronária Aguda. Deveremos Continuar a Reabilitar os Doentes de Baixo Risco? Experiência de um Centro

Introdução: A Reabilitação cardíaca (Rc) é um elemento fundamental na prevenção secundária após síndrome coronária aguda (ScA). A American Association of Cardiovascular and Pulmonary Rehabilitation (AAcPR)definiu critérios de estratificação de risco para os doentes elegíveis para programas de Rc. Contudo, tem sido questionada a integração de doentes de baixo risco em programas estruturados de treino de exercício. Objectivo: comparar o impacto da Rc nos doentes de baixo risco cardiovascular versus risco moderado/alto, segundo os critérios a AAcPR, de forma a avaliar o real benefício da Rc na capacidade de exercício nos doentes de baixo risco, quantificada por prova de esforço cardiorrespiratória (PecR). Métodos: Análise retrospetiva dos doentes submetidos a Rc após ScA e submetidos a PecR antes e após a integração num programa de treino de exercício supervisionado constituído por 36 sessões. Foram incluídos doentes desde janeiro de 2004 a dezembro de 2013, num centro Hospitalar Terciário. Os doentes foram divididos em dois grupos: grupo de risco cardiovascular baixo (GRB) e grupo de doentes com risco moderado a alto (GRMA) de acordo com os critérios da AAcPR. Os parâmetros avaliados na PecR foram: pico de consumo de oxigénio (pVO2), pVO2 em relação ao valor previsto para idade e género (%pVO2), declive da rampa do equivalente ventilatório de dióxido de carbono (Ve/VcO2slope), (Ve/VcO2slope)/pVO2 e potência circulatória de pico (PcP). Resultados: Foram incluídos em programa de Rc, pós ScA, 129 doentes, 86,0% do género masculino, com idade média de 56,3±9,8 anos. Setenta e nove doentes (61,3%) foram incluídos no grupo de baixo risco e 50 doentes (38,7%) no grupo de risco moderado a alto.Comparando os resultados da PecR basal verifica-se uma melhor capacidade funcional nos indivíduos de baixo risco (pVO2 26,7±7,0 versus 23,9±5,7 ml/kg/min; p=0,019). Esta diferença significativa desapareceu após a conclusão do programa de Rc, apresentando o GRB pVO2 final de 28,5±7,3ml/kg/min e o GRMA 27,0±7,0ml/kg/min (p=0,232). Ao confrontar os parâmetros da prova de esforço cardiorrespiratória prévios e após reabilitação cardíaca, verifica-se, em ambos os grupos, um aumento significativo da capacidade funcional expresso pelo aumento do pVO2, (Ve/VcO2slope)/pVO2, PcP e duração da prova. No entanto, apenas no grupo de baixo risco se evidencia uma diminuição signi-ficativa do Ve/VcO2 slope (26,7±6,2 versus 25,7±5,3; p=0,029). A amplitude da melhoria de pVO2 foi menos marcada no GRB (1,8±6,5 ml/kg/min versus 3,1±5,0 ml/kg/min; p=0.133). Um incremento no pVO2 superior a 10% em relação ao valor inicial foi atingido em 41,8% dos doentes no GRB e 58,0% dos doentes no GRMA (p=0,072). Conclusão: independentemente do grau de risco cardiovascular inicial, existe benefício na capacidade funcional de exercício após programa de Rc com 36 sessões de treino de exercício, objetivamente quantificado pelos parâmetros da PecR. No entanto, esta melhoria é mais acentuada nos indivíduos de risco moderado a alto comparativamente aos indivíduos de baixo risco. Atendendo à limitação de recursos, deverá ser privilegiada a inclusão de indivíduos de moderado e alto risco, não subvalorizando, no entanto, o benefício também alcançado pelos indivíduos de baixo risco cardiovascular

Cancer Inhibition and In Vivo Osteointegration and Compatibility of Gallium-Doped Bioactive Glasses for Osteosarcoma Applications

Traditional osteosarcoma therapies tend to focus solely on eradicating residual cancer cells and often fail to promote local bone regeneration and even inhibit it due to lack of precise control over target cells, i.e., the treatment affects both normal and cancer cells. Typically, multistep procedures are required for optimal efficacy. Here, we found that a silica-based bioactive material containing 3 mol % gallium oxide selectively kills human osteosarcoma cells and presents excellent in vivo osteointegration, while showing no local or systemic toxicity. Cell culture media conditioned with the proposed material was able to kill 41% of osteosarcoma cells, and no significant deleterious effect on normal human osteoblasts was observed. In addition, rats treated with the gallium-doped material showed excellent material–bone integration with no sign of local toxicity or implant rejection. Systemic biocompatibility investigation did not indicate any sign of toxicity, with no presence of fibrosis or cellular infiltrate in the histological microstructure of the liver and kidneys after 56 days of observation. Taken together, these results show that synergistic bone regeneration and targeted cancer therapy can be combined, paving the way toward new bone cancer treatment approaches

Excited states of bromopyrimidines probed by vuv photoabsorption spectroscopy and theoretical calculations

Funding Information: Funding: J.P.‐d.‐S. acknowledges the Portuguese National Funding Agency FCT‐MCTES through PhD grant PD/BD/142768/2018, together with R.R., J.A., M.M. and F.F.d.S. through the researcher grant PTDC/FIS‐AQM/31215/2017 and AIL through the researcher grant PTDC/FIS‐ AQM/31281/2017. This work was also supported by Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, PD/00193/2012); UIDB/04378/2020 (UCIBIO); and UIDB/00068/2020 (CEFITEC). The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020.We report absolute photoabsorption cross sections for gas‐phase 2‐ and 5‐ bromopyrimidine in the 3.7–10.8 eV energy range, in a joint theoretical and experimental study. The measurements were carried out using high‐resolution vacuum ultraviolet synchrotron radiation, with quantum chemical calculations performed through the nuclear ensemble approach in combination with time‐dependent density functional theory, along with additional Franck–Condon Herzberg–Teller calculations for the first absorption band (3.7–4.6 eV). The cross sections of both bromopyrimidines are very similar below 7.3 eV, deviating more substantially from each other at higher energies. In the 7.3–9.0 eV range where the maximum cross‐section is found, a single and broad band is observed for 5‐bromopyrimidine, while more discernible features appear in the case of 2‐bromopyrimidine. Several π* ← π transitions account for the most intense bands, while weaker ones are assigned to transitions involving the nitrogen and bromine lone pairs, the antibonding σ*Br orbital, and the lower‐lying Rydberg states. A detailed comparison with the available photo‐absorption data of bromobenzene is also reported. We have found significant differences regarding the main absorption band, which is more peaked in bromobenzene, becoming broader and shifting to higher energies in both bromopyrimidines. In addition, there is a significant suppression of vibrational structures and of Rydberg states in the pair of isomers, most noticeably for 2‐bromopyrimidine.publishersversionpublishe

Lesão do esmalte após remoção de adesivo ortodontico por pedra de Arkansas e pontas laminadas de carbeto de tungsténio

Objectives: The main aim of this study was to compare the effectiveness of two different methods to remove orthodontic composite adhesives from enamel concerning the surface damage and remnant composite adhesive on the surfaces. Methods: Human molars were stored in buffer solution at room temperature before bonding the brackets. Teeth were ultrasonically cleaned in distilled water before bonding procedure. Ninety two brackets were randomly bonded to the buccal surface of twenty three molars using a composite-based adhesive system. After 15 days, the orthodontic composite adhesives were removed by using Arkansas' stone or multi-blade tungsten burs. After debonding process, the remnant composite adhered to the tooth as well as the teeth surfaces were analyzed by photographic images at x40 magnification concerning the (ARI) adhesive remnant or (SRI) surface roughness index. Also, enamel surfaces were inspected by field emission guns scanning electron microscopy (FEGSEM) before bonding and after bracket detachment. The statistical analysis was performed using SPSS® Statistics vs.18.0, considering a significance level of 0.05 to one-way ANOVA. Tukey's test was used for multiple comparisons and Chi-square tests were used to analyze the association between categorical variables. Results: ARI results revealed no statistically significant differences between the two methods of bracket removal (p=0.283). Considering SRI, statistically significant differences were detected between the two procedures (p<0.001) considering all worn surfaces revealed lower surface roughness after removal of adhesive by Arkansas stone than that recorded on worn surfaces after removal using tungsten carbide burs. Conclusion: The removal of orthodontic adhesive promoted less damage on enamel surfaces by using Arkansas stone at low rotation. Nevertheless, finishing procedures can decrease the roughness on enamel without additional damage.Objetivos: O objetivo deste estudo foi comparar a eficácia de dois métodos diferentes de remocâo do compósito utilizado na adesão de brackets, após a realizacão do tratamento ortodôntico. Métodos: Foram utilizados 92 brackets colados em 23 molares previamente selecionados de acordo com os critérios de inclusão/exclusão. Uma vez removidos os brackets, foram então utilizados os dois métodos de remocão de compósito: a) pedras de Arkansas; b) brocas multilaminadas de tungsténio, ambas utilizadas em contra-ângulo (baixa rotacão). Uma vez removido o compósito, foram analisadas e quantificadas as possíveis lesões advindas do procedimento. A área de compósito remanescente foi calculada em todos os dentes. A aná- lise estatística foi realizada utilizando o SPSS® Statistics vs.18.0, considerando um nível de significância de 0,05 para teste ANOVA. O teste de Tukey foi utilizado para comparações múltiplas e Qui-quadrado para análise entre variáveis categóricas. Resultados: Após a remocão do compósito com cada um dos métodos verificou-se que, relativamente ao índice adesivo remanescente (IAR), não existiam diferença estatisticamente significativa (p=0,283) entre métodos de remoção. Entretanto, diferenças em relação ao índice de rugosidade de superfície (IRS) foram estatisticamente significativas (p<0,001) com resultados a favor do método utilizando pedras de Arkansas. Conclusão: Menor dano ao esmalte foi promovido pela remocão de adesivo ortodóntico com uso da pedra de Arkansas. Entretanto, polimento adicional diminui a rugosidade da superfície sem danos adicionais ao esmalte.This work has been supported by FCT (Fundação para a Ciência e Tecnologia – Portugal) in the scope of the project UID/ EEA/04436/ 2013 NORTE-01-0145- FEDER-000018 - HAMaBIC

Long-lived NIR emission in sulfur-doped zeolites due to the presence of [S3]2- clusters

Funding Information: The authors want to acknowledge the Portuguese Foundation for Science and Technology for funding through the grants SFRH/BD/145009/2019 and SFRH/BPD/120599/2016 , the individual contract 2020.00252. CEECIND and several projects PTDC/QUI-QFI/32007/2017, UIDB/04565/2020, UIDP/04565/2020, LA/P/0140/2020, LAQV-REQUIMTE (LA/P/0008/2020, UIDB/50006/2020 and UIDP/50006/2020), VICARTE (UIDP/00729/2020, UIDB/00729/2020) and C2TN (UIDB/04349/2020). MOSTMICRO-ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and by European Union's Horizon 2020 research and innovation program under grant agreement No. 810856. Funding Information: The authors want to acknowledge the Portuguese Foundation for Science and Technology for funding through the grants SFRH/BD/145009/2019 and SFRH/BPD/120599/2016, the individual contract 2020.00252. CEECIND and several projects PTDC/QUI-QFI/32007/2017, UIDB/04565/2020, UIDP/04565/2020, LA/P/0140/2020, LAQV-REQUIMTE (LA/P/0008/2020, UIDB/50006/2020 and UIDP/50006/2020), VICARTE (UIDP/00729/2020, UIDB/00729/2020) and C2TN (UIDB/04349/2020). MOSTMICRO-ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and by European Union's Horizon 2020 research and innovation program under grant agreement No. 810856. Publisher Copyright: © 2023 The Author(s)The exploration of novel long-lived near-infrared (NIR) luminescent materials has attracted significant attention due to their applications in optical communications, anticounterfeiting, and bioimaging. However, these materials usually present low photoluminescence quantum yields and low photo- and chemical stability. Novel emitters that overcome these limitations are in demand. In this study, NIR emission was achieved using widely available, sustainable, and non-toxic materials through the synthesis of sulfur-doped zeolites, with different S/Cl ratios. With a combination of computational calculations (TD-DFT) and spectroscopic data, this emission was assigned to the radiative decay of excited triplet states of [S3]2- clusters, which resulted in a remarkably high Stokes shift (1.97 eV, 440 nm) and an average decay time of 0.54 ms. These new materials present high stability, external quantum efficiency of up to 17%, and a long-lived NIR emission, placing these compounds in a unique position to be used in applications demanding NIR emitters.publishersversionpublishe