4,303 research outputs found

    A kinetic model of the central carbon metabolism for acrylic acid production in Escherichia coli

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    Acrylic acid (AA) is an important chemical that can be used in the production of a broad spectrum of products used on a daily basis, such as diapers, coatings paints, adhesives, textiles, detergents and plastic additives [1]. In addition, this chemical can also be used in the production of a superabsorbent polymer, which further increases its worldwide demand and commercial value in the industrial business [2]. However, most of the AA currently commercialized is produced by the oxidation of propylene or propane [3]. The production of AA contributes to the accumulation of CO2 in the atmosphere and relies on the worlds petroleum reserves, which are not renewable and are in rapid decline [2, 4]. Hence, the need for the development of innovative, clean and sustainable biological methods for the production of AA has attracted considerable attention from the scientific community [2, 5, 6]. In the last few years, there has been an effort to optimize the bio-based production of 3-hydroxypropionic acid (3-HP) by Escherichia coli. In this process, 3-HP is purified and converted to AA by catalytic dehydration. Despite such efforts, this method is still energetically demanding and has high production costs, associated with the catalytic process that takes place in the final step. Hence, the current process for the production of AA is not ideal [2]. A method that does not require the catalytic dehydration of 3-HP was put forward to overcome this issue. This method allows producing AA through fermentation by recombinant E. coli [2, 5]. The aim of this work was to perform the in silico insertion of different alternatives of the heterologous pathways for AA production in kinetic models of the central carbon metabolism of E. coli, which will allow to select the best approach to be implemented in vivo. Five models namely, the Chassagnole [7], the Jaham [8], the Kadir [9], the Peskov [10] and the Khodayari [11] models, were evaluated to select the one that better complies with the requirements of this project. The selected model was used to test the different knock-in strategies. References 1. Rolf Beerthuis, Gadi Rothenberg, and Raveendran Shiju. Catalytic routes towards acrylic acid, adipic acid and -caprolactam starting from biorenewables. Green Chemistry, 17(3):13411361, 2015. 2. Hun Su Chu, Jin Ho Ahn, Jiae Yun, In Suk Choi, TaeWook Nam, and Kwang Myung Cho. Direct fermentation route for the production of acrylic acid. Metabolic Engineering, 32:23 29, 2015. 3. Avelino Corma, Sara Iborra, and Alexandra Velty. Chemical routes for the transformation of biomass into chemicals. Chemical Reviews, 107(6):24112502, 2007. 4. Rojan John, Madhavan Nampoothiri, and Ashok Pandey. Fermentative production of lactic acid from biomass: an overview on process developments and future perspectives. Applied Microbiology and Biotechnology, 74(3):524534, 2007. 5. Wenhua Tong, Ying Xu, Mo Xian, Wei Niu, Jiantao Guo, Huizhou Liu, and Guang Zhao. Biosynthetic pathway for acrylic acid from glycerol in recombinant Escherichia coli. Applied Microbiology and Biotechnology, 100(11):49014907, 2016. 6. Zhijie Liu and Tiangang Liu. Production of acrylic acid and propionic acid by constructing a portion of the 3-hydroxypropionate/4-hydroxybutyrate cycle from Metallosphaera sedula in Escherichia coli. Journal of Industrial Microbiology & Biotechnology, 43(12):1659 1670, 2016. 7. Christophe Chassagnole, Naruemol Noisommit-Rizzi, Joachim W. Schmid, Klaus Mauch, and Matthias Reuss. Dynamic modeling of the central carbon metabolism of Escherichia coli. Biotechnology and Bioengineering, 79(1): 5373, 2002. 8. Nusrat Jahan, Kazuhiro Maeda, Yu Matsuoka, Yurie Sugimoto, and Hiroyuki Kurata. Development of an accurate kinetic model for the central carbon metabolism of Escherichia coli. Microbial Cell Factories, 15(1): 112, 2016. 9. Tuty Kadir, Ahmad Mannan, Andrzej Kierzek, Johnjoe McFadden, and Kazuyuki Shimizu. Modeling and simulation of the main metabolism in Escherichia coli and its several singlegene knockout mutants with experimental verification. Microbial Cell Factories, 9(1): 88, 2010. 10. Kirill Peskov, Ekaterina Mogilevskaya, and Oleg Demin. Kinetic modelling of central carbon metabolism in Escherichia coli. FEBS Journal, 279(18): 33743385, 2012. 11. Ali Khodayari, Ali Zomorrodi, James Liao, and Costas Maranas. A kinetic model of Escherichia coli core metabolism satisfying multiple sets of mutant flux data. Metabolic Engineering, 25: 5062, 2014Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/ 04469 / 2019 unit and BioTecNorte operation (NORTE - 01 - 0145 - FEDER - 000004 ) funded by the European Regional Development Fund under the scope of Norte 2020 - Programa Operacional Regional do Norteinfo:eu-repo/semantics/publishedVersio

    Association of radio polar cap brightening with bright patches and coronal holes

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    Radio-bright regions near the solar poles are frequently observed in Nobeyama Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal holes. However, the origin of these polar brightening has not been established yet. We propose that small magnetic loops are the source of these bright patches, and present modeling results that reproduce the main observational characteristics of the polar brightening within coronal holes at 17 GHz. The simulations were carried out by calculating the radio emission of the small loops, with several temperature and density profiles, within a 2D coronal hole atmospheric model. If located at high latitudes, the size of the simulated bright patches are much smaller than the beam size and they present the instrument beam size when observed. The larger bright patches can be generated by a great number of small magnetic loops unresolved by the NoRH beam. Loop models that reproduce bright patches contain denser and hotter plasma near the upper chromosphere and lower corona. On the other hand, loops with increased plasma density and temperature only in the corona do not contribute to the emission at 17 GHz. This could explain the absence of a one-to-one association between the 17 GHz bright patches and those observed in extreme ultraviolet. Moreover, the emission arising from small magnetic loops located close to the limb may merge with the usual limb brightening profile, increasing its brightness temperature and width.Comment: 8 pages, 6 figures, 1 table. Accepted for publication in The Astrophysical Journa

    Influence of delivery method on neuroprotection by bone marrow mononuclear cell therapy following ventral root reimplantation with fibrin sealant

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOThe present work compared the local injection of mononuclear cells to the spinal cord lateral funiculus with the alternative approach of local delivery with fibrin sealant after ventral root avulsion (VRA) and reimplantation. For that, female adult Lewis rats were divided into the following groups: avulsion only, reimplantation with fibrin sealant; root repair with fibrin sealant associated with mononuclear cells; and repair with fibrin sealant and injected mononuclear cells. Cell therapy resulted in greater survival of spinal motoneurons up to four weeks post-surgery, especially when mononuclear cells were added to the fibrin glue. Injection of mononuclear cells to the lateral funiculus yield similar results to the reimplantation alone. Additionally, mononuclear cells added to the fibrin glue increased neurotrophic factor gene transcript levels in the spinal cord ventral horn. Regarding the motor recovery, evaluated by the functional peroneal index, as well as the paw print pressure, cell treated rats performed equally well as compared to reimplanted only animals, and significantly better than the avulsion only subjects. The results herein demonstrate that mononuclear cells therapy is neuroprotective by increasing levels of brain derived neurotrophic factor (BDNF) and glial derived neurotrophic factor (GDNF). Moreover, the use of fibrin sealant mononuclear cells delivery approach gave the best and more long lasting results.The present work compared the local injection of mononuclear cells to the spinal cord lateral funiculus with the alternative approach of local delivery with fibrin sealant after ventral root avulsion (VRA) and reimplantation. For that, female adult Lewis98113FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2010/0986-5; 2010/00729-2sem informaçãosem informaçã

    Associação entre características de desempenho de tilápia-do-nilo ao longo do período de cultivo.

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    O objetivo deste trabalho foi estimar as herdabilidades e a estrutura de correlações genéticas entre as características de desempenho de tilápia-do-nilo (Oreochromis niloticus) da linhagem GIFT, em diferentes estágios do ciclo de produção. As tilápias foram cultivadas em tanques - rede. Mediu-se ganho em peso diário total, peso vivo e ganho em peso diário, em quatro períodos, com intervalos de aproximadamente 30 dias. Foram realizadas análises unicaracter para as medidas, em todas as biometrias e, nas análises bicaracter, as medidas de mesma característica foram combinadas duas a duas e com o ganho em peso diário total. As estimações de herdabilidade variaram de 0,15 a 0,11 para peso vivo, 0,16 a 0,09 para ganho em peso diário e 0,17 a 0,12 para ganho em peso diário total, nas análises unicaracter. Os valores estimados de correlação genética para peso vivo e ganho em peso diário, associados ao ganho em peso diário total, variaram entre 0,37 a 0,98 e 0,74 a 0,8 respectivamente. A forte associação genética estimada entre peso vivo em biometrias intermediárias e ganho em peso diário total sugere que a seleção para velocidade de crescimento pode ser realizada de forma precoce

    New endoscopic procedure for bladder wall closure: results from the porcine model

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    Upper urinary tract urothelial carcinomas are usually managed by radical nephroureterectomy (RNU), often followed by intravesical chemotherapy to minimize recurrence. Open surgery is the gold standard procedure for RNU, but it associates with high morbidity, and it has been increasingly replaced by minimally invasive strategies, such as laparoscopy and endoscopy. Although effective, endoscopic ureteral excision leaves the bladder unsutured, increasing the risk of tumor spillage, and precluding the immediate administration of intravesical chemotherapy. Here we describe a new method to close the bladder wall after ureteral excision, using barbed sutures via the endoscopic access. Our results in 8 female pigs demonstrate that this method is effective to close the bladder wall. The procedure was completed in a median time of 24 min, and no adverse events were registered in the follow-up or at the three-week necropsy. This technique improves a previous approach described by our group because the device is more flexible and allows to tie the knots inside the bladder. Barbed sutures have been used in the clinical practice for other types of surgeries, and therefore this method can further be adapted to human patients with no safety concerns. Its use may allow to administer intravesical chemotherapy, which reduces tumor recurrence and improves patient outcomes.The authors acknowledge Ana Goios for support in manuscript writing and technical editing, and for producing original illustrations for Figure 3. Doctoral grant of CUF Jose de Mello Saude

    Diclidophora luscae (Monogenea: Diclidophoridae) in pouting, Trisopterus luscus (Linnaeus, 1758) from the northeast Atlantic; epidemiology, morphology, molecular and phylogenetic analysis

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    Diclidophora (Monogenea) species are gill parasites with a stenoxenic specifcity occurring only in Gadiformes. Epidemiologi‑cal, morphological, molecular and phylogenetic studies were performed on 594 Diclidophora specimens collected from 213 Trisopterus luscus captured in the northeast Atlantic of the Portuguese coast during 2012, 2013 and 2020. Prevalence, parasite abundance and infection intensity were determined. Positive correlation between fsh weight and length and infection intensity was observed. The efects of preservation on the parasite morphological features were studied, highlighting that specimen’s identifcation should be reinforced by molecular studies. A sequence of D. luscae capelanii from T. capelanus captured in the Mediterranean Sea included in the 28S rDNA molecular analysis was nested within a robust D. luscae clade. Data analysis suggested that this species is in fact D. luscae, which is compatible with T. luscus and T. capelanus. The identity of fsh hosts was confrmed by barcoding. For the frst time, data on the infection parameters is shown, highlighting the importance of including this parasite in the monitoring plans for a holistic approach with possible efects for the management of pouting resources aiming of attaining sustainable development and biodiversity conservation measures, according to the 14th objective of the 2030 agendainfo:eu-repo/semantics/publishedVersio

    Zika Virus Infection Causes Temporary Paralysis in Adult Mice With Motor Neuron Synaptic Retraction and Evidence for Proximal Peripheral Neuropathy

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    Clinical evidence is mounting that Zika virus can contribute to Guillain-Barré syndrome which causes temporary paralysis, yet the mechanism is unknown. We investigated the mechanism of temporary acute flaccid paralysis caused by Zika virus infection in aged interferon αβ-receptor knockout mice used for their susceptibility to infection. Twenty-five to thirty-five percent of mice infected subcutaneously with Zika virus developed motor deficits including acute flaccid paralysis that peaked 8-10 days after viral challenge. These mice recovered within a week. Despite Zika virus infection in the spinal cord, motor neurons were not destroyed. We examined ultrastructures of motor neurons and synapses by transmission electron microscopy. The percent coverage of motor neurons by boutons was reduced by 20%; more specifically, flattened-vesicle boutons were reduced by 46%, and were normalized in recovering mice. Using electromyographic procedures employed in people to help diagnose Guillain-Barré syndrome, we determined that nerve conduction velocities between the sciatic notch and the gastrocnemius muscle were unchanged in paralyzed mice. However, F-wave latencies were increased in paralyzed mice, which suggests that neuropathy may exist between the sciatic notch to the nerve rootlets. Reversible synaptic retraction may be a previously unrecognized cofactor along with peripheral neuropathy for the development of Guillain-Barré syndrome during Zika virus outbreaks

    A kinetic model of the central carbon metabolism for acrylic acid production in Escherichia coli

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    Acrylic acid is an economically important chemical compound due to its high market value. Nevertheless, the majority of acrylic acid consumed worldwide its produced from petroleum derivatives by a purely chemical process, which is not only expensive, but it also contributes towards environment deterioration. Hence, justifying the current need for sustainable novel production methods that allow higher profit margins. Ideally, to minimise production cost, the pathway should consist in the direct bio-based production from microbial feedstocks, such as Escherichia coli, but the current yields achieved are still too low to compete with conventional method. In this work, even though the glycerol pathway presented higher yields, we identified the malonyl-CoA route, when using glucose as carbon source, as having the most potential for industrial-scale production, since it is cheaper to implement. Furthermore, we also identified potential optimisation targets for all the tested pathways, that can help the bio-based method to compete with the conventional process.This study was supported by the Portuguese Foundation for Science and Technology(FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. This article is also a result of the project 22231/01/SAICT/2016: “Biodata.pt – Infraestrutura Portuguesa de Dados Biolo´gicos”, by Lisboa Portugal Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Alexandre Oliveira holds a doctoral fellowship (2020.10205.BD) provided by the FCT. Oscar Dias acknowledge FCT for the Assistant Research contract obtained under CEEC Individual 2018. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

    Glatiramer Acetate Treatment Increases Stability Of Spinal Synapses And Down Regulates Mhc I During The Course Of Eae.

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    The recent discovery that the major histocompatibility complex of class I (MHC I) expression has a role in the synaptic elimination process, represented an insight into understanding the cross talk between neurons. In the present study, the possibility that glatiramer acetate (GA) treatment influences the MHC class I expression and the synaptic plasticity process in the spinal cord during the course of EAE was investigated. C57BL/6J mice were induced to EAE and submitted to treatment either with a placebo solution or with GA (0.05 mg/animal, subcutaneously, on a daily basis). All the animals were sacrificed at the peak disease (14 days after induction) or at the point of recovery of the clinical signs (21 days after induction). The spinal cords were removed and submitted to immunohistochemical examination, Western blotting and transmission electron microscopy analysis. The results showed that GA treatment was able to decrease synaptic loss during the course of EAE, which correlates with the downregulation of the MHC I complex. The present results reinforce the neuroprotective role of GA treatment, by reducing synaptic loss during the course of the disease. Such action may be associated with the recently described role of MHC I regulation during the synaptic plasticity process.71188-20

    Optimal design of THEDES based on Perillyl Alcohol and Ibuprofen

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    Therapeutic deep eutectic systems (THEDES) have dramatically expanded their popularity in the pharmaceutical field due to their ability to increase active pharmaceutical ingredients (APIs) bioavailability. However, their biological performance has not yet been carefully scrutinized. Herein, THEDES based on the binary mixture of perillyl alcohol (POH) and ibuprofen (IBU) were prepared using different molar ratios. Our comprehensive strategy includes the characterization of their thermal and structural behavior to identify the molar ratios that successfully form deep eutectic systems. The in vitro solubility of the different systems prepared has demonstrated that, unlike other reported examples, the presence of the terpene did not affect the solubility of the anti-inflammatory agent in a physiological simulated media. The biological performance of the systems was studied in terms of their antimicrobial activity against a wide panel of microorganisms. The examined THEDES showed relevant antimicrobial activity against all tested microbial strains, with the exception of P. aeruginosa. A synergistic effect from the combination of POH and IBU as a eutectic system was verified. Furthermore, the cytotoxic profile of these eutectic systems towards colorectal cancer (CRC) in vitro cell models was also evaluated. The results provide the indication that the cell viability varies in a dose-dependent manner, with a selective THEDES action towards CRC cells. With tunable bioactivities in a ratio-dependent manner, THEDES enhanced the antimicrobial and anticancer properties, representing a possible alternative to conventional therapies. Therefore, this study provides foreseeable indications about the utility of THEDES based on POH and IBU as strong candidates for novel active pharmaceutical systems.Foundation for Science and Technology (FCT), through project PTDC/BBB-490 EBB/1676/2014–Des.Zyme, Light2Skin-PTDC/CTM-CTM/29813/2017 and ERC-2016-CoG 725034 (ERC Consolidator Grant Des.solve). E.S. would also like to acknowledge the financial support by the FCT through the doctoral grant with reference number SFHR/BD/143902/2019. J.M.S. would also like to acknowledge the financial support by the FCT through the post-doctoral grant with reference number SFRH/BPD/116779/201
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