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

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

Managing patients with dengue fever during an epidemic: the importance of a hydration tent and of a multidisciplinary approach

<p>Abstract</p> <p>Background</p> <p>Dengue fever is one of the most common tropical diseases worldwide. Early detection of the disease, followed by intravenous fluid therapy in patients with dengue hemorrhagic fever (DHF) or with warning signs of dengue has a major impact on the prognosis. The purpose of this study is to describe the care provided in a hydration tent, including early detection, treatment, and serial follow-up of patients with dengue fever.</p> <p>Findings</p> <p>The analysis included all patients treated in the hydration tent from April 8 to May 9, 2008. The tent was set up inside the premises of the 2^ndMilitary Firemen Group, located in Meier, a neighborhood in Rio de Janeiro, Brazil. The case form data were stored in a computerized database for subsequent assessment. Patients were referred to the tent from primary care units and from secondary city and state hospitals. The routine procedure consisted of an initial screening including vital signs (temperature, blood pressure, heart rate, and respiratory rate), tourniquet test and blood sampling for complete blood count. Over a 31-day period, 3,393 case recordings were seen at the hydration tent. The mean was 109 patients per day. A total of 2,102 initial visits and 1,291 return visits were conducted. Of the patients who returned to the hydration tent for reevaluation, 850 returned once, 230 returned twice, 114 returned three times, and 97 returned four times or more. Overall, 93 (5.3%) patients with DHF seen at the tent were transferred to a tertiary hospital. There were no deaths among these patients.</p> <p>Discussion</p> <p>As the epidemics were already widespread and there were no technical conditions for routine serology, all cases of suspected dengue fever were treated as such. Implementing hydration tents decrease the number of dengue fever hospitalizations.</p

Effect of dietary organic acids and humic substance supplementation on performance, immune response and gut morphology of broiler chickens

This study evaluated the additive effects of a commercial feed supplementation blend (Ava Cid P)—consisting of humic substances, coated sodium butyrate, and a small acidifier portion— on the growth, immune response, and gut health of broiler chickens. A total of 540 female and 540 male broilers were raised from 1–49 d. On the first day, the animals were distributed in a completely randomized 2 × 5 factorial design (2 sexes and 5 treatments) with 7 replications of 15 birds each. The 5 treatments were 1) birds did not receive Ava Cid P (control); 2) birds received 0.91 kg/t of Ava Cid P from 1–21 d (AVA1–21); 3) birds received 0.91 kg/t of Ava Cid P from 1–21 d and 0.45 kg/t from 22–35 d (AVA1–35); 4) birds received 0.91 kg/t of Ava Cid P from 1–21 d and 0.45 kg/t from 22–42 d (AVA1–42); and 5) birds received 0.91 kg/t of Ava Cid P from 1–21 d, 0.45 kg/t from 22–35 d, and 0.23 kg/t from 36–49 d (AVA1–49). ANOVA and Tukey’s tests were applied to compare the means (P < 0.05) between treatments. The Ava Cid P showed no effect on male or female growth performance or goblet cell density. However, the supplement modified gut morphometry, and jejunum villi were 32% higher at 9 and 35 d in the AVA1–35 birds compared with those of the control group. The apparent villus surface and villus height increased by 87% and 46%, respectively, in the AVA1–49 birds compared with the AVA1–21 birds. The expression of mucin 2 (MUC2) and tumor necrosis factor-alpha (TNF-α) were 1.6% and 0.9% lower in the AVA1–21 birds than in the control birds, but no effects were observed for interleukin-1 beta and interleukin-10. The Ava Cid P altered the mRNA expression of MUC2 and TNF-α and some characteristics of intestinal morphometry, but did not change the performance of broilers

Effect of transcranial direct current stimulation on exercise performance: a systematic review and meta-analysis

Background: Transcranial direct current stimulation (tDCS) has been used to improve exercise performance, though the protocols used, and results found are mixed. Objective: We aimed to analyze the effect of tDCS on improving exercise performance. Methods: A systematic search was performed on the following databases, until December 2017: PubMed/MEDLINE, Embase, Web of Science, SCOPUS, and SportDiscus. Full-text articles that used tDCS for exercise performance improvement in adults were included. We compared the effect of anodal (anode near nominal target) and cathodal (cathode near nominal target) tDCS to a sham/control condition on the outcome measure (performance in isometric, isokinetic or dynamic strength exercise and whole-body exercise). Results: 22 studies (393 participants) were included in the qualitative synthesis and 11 studies (236 participants) in the meta-analysis. The primary motor cortex (M1) was the main nominal tDCS target (n = 16; 72.5%). A significant effect favoring anodal tDCS (a-tDCS) applied before exercise over M1 was found on cycling time to exhaustion (mean difference = 93.41 s; 95%CI = 27.39 s to 159.43 s) but this result was strongly influenced by one study (weight = 84%), no effect was found for cathodal tDCS (c-tDCS). No significant effect was found for a-tDCS applied on M1 before or during exercise on isometric muscle strength of the upper or lower limbs. Studies regarding a-tDCS over M1 on isokinetic muscle strength presented mixed results. Individual results of studies using a-tDCS applied over the prefrontal and motor cortices either before or during dynamic muscle strength testing showed positive results, but performing meta-analysis was not possible. Conclusion: For the protocols tested, a-tDCS but not c-tDCS vs. sham over M1 improved exercise performance in cycling only. However, this result was driven by a single study, which when removed was no longer significant. Further well-controlled studies with larger sample sizes and broader exploration of the tDCS montages and doses are warranted

Triceps surae muscle-tendon properties as determinants of the metabolic cost in trained long-distance runners

Purpose: This study aimed to determine whether triceps surae’s muscle architecture and Achilles tendon parameters are related to running metabolic cost (C) in trained long-distance runners. Methods: Seventeen trained male recreational long-distance runners (mean age = 34 years) participated in this study. C was measured during submaximal steady-state running (5 min) at 12 and 16 km h–1 on a treadmill. Ultrasound was used to determine the gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus (SO) muscle architecture, including fascicle length (FL) and pennation angle (PA), and the Achilles tendon cross-sectional area (CSA), resting length and elongation as a function of plantar flexion torque during maximal voluntary plantar flexion. Achilles tendon mechanical (force, elongation, and stiffness) and material (stress, strain, and Young’s modulus) properties were determined. Stepwise multiple linear regressions were used to determine the relationship between independent variables (tendon resting length, CSA, force, elongation, stiffness, stress, strain, Young’s modulus, and FL and PA of triceps surae muscles) and C (J kg–1m–1) at 12 and 16 km h–1. Results: SO PA and Achilles tendon CSA were negatively associated with C (r2 = 0.69; p < 0.001) at 12 km h–1, whereas SO PA was negatively and Achilles tendon stress was positively associated with C (r2 = 0.63; p = 0.001) at 16 km h–1, respectively. Our results presented a small power, and the multiple linear regression’s cause-effect relation was limited due to the low sample size. Conclusion: For a given muscle length, greater SO PA, probably related to short muscle fibers and to a large physiological cross-sectional area, may be beneficial to C. Larger Achilles tendon CSA may determine a better force distribution per tendon area, thereby reducing tendon stress and C at submaximal speeds (12 and 16 km h–1). Furthermore, Achilles tendon morphological and mechanical properties (CSA, stress, and Young’s modulus) and triceps surae muscle architecture (GM PA, GM FL, SO PA, and SO FL) presented large correlations with C

A simple method for the quantification of diclofenac potassium in oral suspension by high-performance liquid chromatography with UV-detection

A rapid, simple and low cost method was developed to determine diclofenac potassium (DP) in oral suspension, using a reverse-phase column (C8, 150 mm x 4.6 mm, 5 µm), mobile phase containing methanol/buffer phosphate (70:30 v/v, pH 2.5), at a flow rate of 1.0 mL/min, isocratic method, and ultraviolet detection at 275 nm. A linear response (r = 1.0000) was observed in the range of 10.0-50.0 µg/mL. Validation parameters such as linearity, specificity, precision, accuracy and robustness were evaluated. The method presented precision (repeatability: relative standard deviation = 1.21% and intermediate precision: between-analyst = 0.85%). The specificity of the assay was evaluated by exposure of diclofenac potassium under conditions of stress such as hydrolysis, photolysis, oxidation and high temperature. The method presented accuracy values between 98.28% and 101.95%. The results demonstrate the validity of the proposed method that allows determination of diclofenac potassium in oral suspension and may be used as an alternative method for routine analysis of this product in quality control

Perfil nutricional lipídico de achigã proveniente de várias albufeiras do Alentejo

A importância da pesca recreativa de águas interiores aumentou significativamente nos últimos 20 anos em território nacional, contribuindo para o desenvolvimento de diversas áreas rurais localizadas perto dos principais pesqueiros. Apesar de atualmente possuir uma menor relevância quando comparada com a pesca profissional realizada em ambientes marinhos ou estuarinos, a pesca em águas interiores possui também um elevado interesse económico e gastronómico, envolvendo um grande número de participantes. Em Portugal, os locais de maior preferência para a pesca recreativa e/ou desportiva são as albufeiras. Todavia este tipo de ecossistema apresenta particularidades, nomeadamente as localizadas nas zonas mediterrânicas como é o caso do Alentejo, sendo de destacar as baixas concentrações de oxigénio associadas à eutrofização na época estival (Almeida et al., 2017). O achigã (Micropterus salmoides Lacépède, 1802) é uma das espécies mais procuradas pelos pescadores recreativos em todo o mundo. Em Portugal, e sobretudo no Alentejo, esta espécie não-indígena continua a ser muito consumida pelos pescadores, sendo que em algumas regiões é mesmo descrita como um importante produto gastronómico e cultural. Todavia, não existe qualquer informação sobre o perfil nutricional da sua parte edível. A sustentabilidade dos recursos naturais, aliada à qualidade do pescado, são desafios que preocupam a sociedade atual e para o qual os consumidores exigem resposta

Infrared fixed point in quantum Einstein gravity

We performed the renormalization group analysis of the quantum Einstein gravity in the deep infrared regime for different types of extensions of the model. It is shown that an attractive infrared point exists in the broken symmetric phase of the model. It is also shown that due to the Gaussian fixed point the IR critical exponent $\nu$ of the correlation length is 1/2. However, there exists a certain extension of the model which gives finite correlation length in the broken symmetric phase. It typically appears in case of models possessing a first order phase transitions as is demonstrated on the example of the scalar field theory with a Coleman-Weinberg potential.Comment: 9 pages, 7 figures, final version, to appear in JHE