•1,3-Dibenzylthiourea/DBTU and 1-benzyl-3-diisopropylthiourea/DPTU were studied.•DPTU and DBTU act as good corrosion inhibitors for C-steel in acid solution.•The inhibition efficiency of DPTU and ...DBTU increased with concentration.•DBU did not act as an effective corrosion inhibitor for C-steel in acid solution.•The sulphur atom may play an important role in the inhibition process.
The behaviour of 1,3-dibenzylthiourea (DBTU) and 1-benzyl-3-diisopropylthiourea (DPTU) have been investigated as carbon steel corrosion inhibitors in HCl solution by weight loss measurements, potentiodynamic polarization curves, electrochemical impedance and scanning electron microscopy analysis. Quantum chemical calculation was applied to correlate electronic structure parameters of thiourea derivatives with their inhibition performances. DPTU results were slightly superior to those obtained in the presence of DBTU, showing that the replacement of one benzyl group for two isopropyl groups enhances the inhibitory properties. The 1,3-dibenzylurea derivative has also been studied in order to assess the importance of the sulphur atom to the inhibitory effect.
Ischemic preconditioning (IPC) of one or two limbs improves performance of exercise that recruits the same limb(s). However, it is unclear whether IPC application to another limb than that in ...exercise is also effective and which mechanisms are involved. We investigated the effect of remote IPC (RIPC) on muscle fatigue, time to task failure, forearm hemodynamics, and deoxygenation during handgrip exercise. Thirteen men underwent RIPC in the lower limbs or a control intervention (CON), in random order, and then performed a constant load rhythmic handgrip protocol until task failure. Rates of contraction and relaxation (ΔForce/ΔTime) were used as indices of fatigue. Brachial artery blood flow and conductance, besides forearm microvascular deoxygenation, were assessed during exercise. RIPC attenuated the slowing of contraction and relaxation throughout exercise (P < 0.05 vs CON) and increased time to task failure by 11.2% (95% confidence interval: 0.7–21.7%, P <0.05 vs CON). There was no significant difference in blood flow, conductance, and deoxygenation between conditions throughout exercise (P > 0.05). In conclusion, RIPC applied to the lower limbs delayed the development of fatigue during handgrip exercise, prolonged time to task failure, but was not accompanied by changes in forearm hemodynamics and deoxygenation.
•BjussuLAAO-II is a snake venom toxin with cytotoxic effects towards Caco-2 cells.•The toxin induces necrosis, apoptosis, oxidative stress, and DNA damage.•The toxin reduces cell viability by acting ...on multiple intracellular targets.•The toxin upregulates the inflammatory cytokine genes TNF and IL6 expression.•The toxin downregulates the apoptotic-related genes BAX, BCL2 and RELA expression.
Colorectal carcinoma is one of the most common cancers in adults. As chemotherapy, the first-choice treatment for colorectal carcinoma, is often infeasible due to acquired tumor resistance and several adverse effects, it is important to discover and explore new molecules with better therapeutic action. Snake venom toxins have shown promising results with high cytotoxicity against tumor cells, but their mechanisms of action remain unclear. Here we examined how BjussuLAAO-II, an L-amino acid oxidase isolated from Bothrops jararacussu snake venom, exerts cytotoxicity towards colorectal adenocarcinoma human cells (Caco-2) and human umbilical vein endothelial cell line (HUVEC). A 24-h treatment with BjussuLAAO-II at 0.25 − 5.00 μg/mL diminished cell viability by decreasing (i) mitochondrial activity, assessed by reduction of 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and resazurin; (ii) the activity of acid phosphatases; and (iii) lysosomal function, assessed by neutral red uptake. BjussuLAAO-II also increased intracellular levels of reactive oxygen species and DNA damage, as assessed by fluorescence and the comet assay, respectively. BjussuLAAO-II altered the expression of cell proliferation-related genes, as determined by RT-qPCR: it elevated the expression of the inflammatory cytokine genes TNF and IL6, and lowered the expression of the apoptotic-related genes BAX, BCL2, and RELA. Therefore, BjussuLAAO-II induces Caco-2 cells death by acting on multiple intracellular targets, providing important data for further studies to assess whether these effects are seen in both tumor and normal cells, with the aim of selecting this drug for possible therapeutic purposes in the future.
Obstructive sleep apnoea syndrome (OSAS) often coexists in patients with chronic obstructive pulmonary disease (COPD). The present prospective cohort study tested the effect of OSAS treatment with ...continuous positive airway pressure (CPAP) on the survival of hypoxaemic COPD patients. It was hypothesised that CPAP treatment would be associated with higher survival in patients with moderate-to-severe OSAS and hypoxaemic COPD receiving long-term oxygen therapy (LTOT). Prospective study participants attended two outpatient advanced lung disease LTOT clinics in São Paulo, Brazil, between January 1996 and July 2006. Of 603 hypoxaemic COPD patients receiving LTOT, 95 were diagnosed with moderate-to-severe OSAS. Of this OSAS group, 61 (64%) patients accepted and were adherent to CPAP treatment, and 34 did not accept or were not adherent and were considered not treated. The 5-yr survival estimate was 71% (95% confidence interval 53-83%) and 26% (12-43%) in the CPAP-treated and nontreated groups, respectively (p<0.01). After adjusting for several confounders, patients treated with CPAP showed a significantly lower risk of death (hazard ratio of death versus nontreated 0.19 (0.08-0.48)). The present study found that CPAP treatment was associated with higher survival in patients with moderate-to-severe OSAS and hypoxaemic COPD receiving LTOT.
Abstract Cowpea is a leguminous plant belonging to the fabaceae family cultivated in the North and Northeast regions of Brazil, with productive potential. Among the abiotic factors, water deficiency ...is one of the main environmental limitations that influence agricultural production in the world. The objective of this work was to study the relative water content and osmoregulators of cowpea plants subjected to water stress. The experiment was carried out in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA, Belém, PA), cowpea plants BR-17 Gurguéia Vigna unguiculata (L.) Walp were used. The experimental design was completely randomized (DIC) in a 2 × 2 factorial scheme, two water conditions (control and water deficit) and two times of stress (four and six days of water suspension), with 7 replications, totaling 28 experimental units. The water deficit affected plants, causing a reduction in relative water content (69.98%), starch (12.84% in leaves and 23.48% in roots) and carbohydrates (84.34%), and an increase in glycine-betaine, sucrose (114.11% in leaves and 18.71% in roots) and proline (358.86%) at time 2. The relative water content was negatively affected by water conditions, with a decrease in relation to the interaction of the aerial part and the root system. Therefore, greater metabolic responses were noted in plants that were subjected to stress treatment at time 2 (6 days).
Resumo O feijão-caupi é uma planta leguminosa pertencente à família das Fabaceae cultivada nas regiões Norte e Nordeste do Brasil, com potencial produtivo. Entre os fatores abióticos, a deficiência hídrica é uma das principais limitações ambientais que influenciam a produção agrícola no mundo. O objetivo do trabalho foi estudar o conteúdo relativo de água e os osmorreguladores de plantas de feijão-caupi submetidas ao estresse hídrico. O experimento foi conduzido em casa de vegetação da Universidade Federal Rural da Amazônia (UFRA, Belém, PA), foram utilizadas plantas de feijão-caupi BR-17 Gurguéia Vigna unguiculata (L.) Walp. O delineamento experimental foi inteiramente casualizado (DIC) em esquema fatorial 2 × 2, duas condições hídricas (controle e déficit hídrico) e dois tempos de estresse (quatro e seis dias de suspensão hídrica), com 7 repetições, totalizando 28 unidades experimentais. O estresse hídrico afetou as plantas, provocando redução no conteúdo relativos de água (69,98%), amido (12,84% nas folhas e 23,48% nas raízes) e carboidratos (84,34%), e aumento na glicina-betaína, sacarose (114,11% nas folhas e 18,71% nas raízes) e prolina (358,86%) no tempo 2. O conteúdo relativo de água foi afetado negativamente pelas condições hídricas, com diminuição em relação à interação da parte aérea e do sistema radicular. Diante disso, notou-se maiores respostas metabólicas nas plantas que foram submetidas ao tratamento de estresse no tempo 2 (6 dias).
The literature lacks studies investigating the performance of supplemented replacement heifers grazing on intensively managed warm-season pasture. Our objective was to evaluate the effects of ...supplement composition (energetic or protein) on the performance, muscle development, thermogenisis, nutrient intake, and digestibility of replacement Holstein heifers grazing Mombaça grass. Eighteen Holstein heifers with an average age and initial body weight (BW) of 12.57 ± 2.54 mo and 218.76 ±47.6 kg, respectively, were submitted to a randomized block design, with six replicates on a rotational grazing system of Panicum maximum cv. Mombaça pasture. Treatments were: control (CON; mineral salt ad libitum); energy supplement (ENE; corn meal as supplement, 8% CP and 3.78 Mcal/kg DE); and protein supplement (PRO; corn and soybean meal, 25% CP and 3.66 Mcal/kg DE). Supplements were individually fed at 0.5% BW. The experiment lasted 120 days, subdivided into three periods. Titanium dioxide and indigestible neutral detergent fiber (iNDF) were used to estimate the intakes and digestibility of the nutrients. BW, wither height, thoracic circumference, body length, and ultrasound of ribeye fat thickness measurements were taken once per period. Body condition score (BCS) was assessed twice during the experiment. The MIXED procedure of SAS, including period as a repeated measure, was used and significance was declared at P ≤ 0.05. Dry matter intake (DMI), CP intake (CPI) and DE intake were greater in heifers fed PRO compared to CON and ENE. Heifers supplemented with ENE had the lowest DMI. Treatment affected pasture intake/BW; it was similar between PRO and CON heifers, and lower for the ENE treatment. A treatment × period interaction was observed for NDF intake (%BW), in which heifers fed PRO and CON had the greatest NDF intake and ENE had the lowest. The digestibility of DM was the greatest in PRO-supplemented heifers and the lowest in CON heifers. Heifers fed ENE had decreased CP digestibility compared to PRO and CON heifers. Average daily gain (ADG) and thoracic circumference gain were greatest in the PRO treatment. BCS was greater in PRO compared to CON and ENE heifers. Supplementing Holstein heifers at 0.5% BW using PRO supplementation resulted in better animal performance, primarily greater ADG, than feeding ENE or not supplementing (CON). In conclusion, our results indicate that dairy heifers should be fed a protein supplement when grazing intensively managed Mombaça grass pasture.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•A simple ultrasound assisted ionic liquid dispersive microextraction was used.•Ultrasound extraction was completed in a short time.•High enrichment factor and low limit of detection for tin were ...found.•Optimization of UA-IL-DLLME was performed with two level full factorial design.•A green microextraction method was applied to foods by ETAAS.
This paper proposes a simple, rapid and green ultrasound assisted and ionic liquid dispersive microextraction procedure using pyrocatechol violet (PV) as complexing reagent and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide C6MIMTf2N as ionic liquid for the detection of tin employing electrothermal atomic absorption spectrometry (ETAAS). The optimization step was performed using a two-level full factorial design involving the following factors: pH of the working media, amount reagents, ionic liquid volume and extraction time and the chemometric response was tin recovery. The procedure allowed the determination of tin with limits of detection and quantification of 3.4 and 11.3 ng L−1, respectively. The relative standard deviation was 4.5% for a tin solution of 0.50 µg L−1. The validation method was confirmed by analysis of rice flour certified reference material. The method was applied for the quantification of tin in several food samples. The concentration range found varied from 0.10 to 1.50 µg g−1.
Infections are one of the main reasons for removal of implants from patients, and usually need difficult and expensive treatments. Staphylococcus aureus and Staphylococcus epidermidis are the most ...frequently detected pathogens. We reviewed the epidemiology and pathogenesis of implant-related infections. Relevant studies were identified by electronic searching of the following databases: PubMed, ScienceDirect, Academic Google, and CAPES Journal Portal. This review reports epidemiological studies of implant infections caused by S. aureus and S. epidermidis. We discuss some methodologies used in the search for new compounds with antibiofilm activity and the main strategies for biomaterial surface modifications to avoid bacterial plaque formation and consequent infection. S. aureus and S. epidermidis are frequently involved in infections in catheters and orthopaedic/breast implants. Different methodologies have been used to test the potential antibiofilm properties of compounds; for example, crystal violet dye is widely used for in-vitro biofilm quantification due to its low cost and good reproducibility. Changes in the surface biomaterials are necessary to prevent biofilm formation. Some studies have investigated the immobilization of antibiotics on the surfaces of materials used in implants. Other approaches have been used as a way to avoid the spread of bacterial resistance to antimicrobials, such as the functionalization of these surfaces with silver and natural compounds, as well as the electrical treatment of these substrates.
The aim of this Intensive Care Medicine Rapid Practice Guideline (ICM-RPG) is to formulate an evidence-based guidance for the use of neuromuscular blocking agents (NMBA) in adults with acute ...respiratory distress syndrome (ARDS). The panel comprised 20 international clinical experts from 12 countries, and 2 patient representatives. We adhered to the methodology for trustworthy clinical practice guidelines and followed a strict conflict of interest policy. We convened panelists through teleconferences and web-based discussions. Guideline experts from the guidelines in intensive care, development, and evaluation Group provided methodological support. Two content experts provided input and shared their expertise with the panel but did not participate in drafting the final recommendations. We followed the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the certainty of evidence and grade recommendations and suggestions. We used the evidence to decision framework to generate recommendations. The panel provided input on guideline implementation and monitoring, and suggested future research priorities. The overall certainty in the evidence was low. The ICM-RPG panel issued one recommendation and two suggestions regarding the use of NMBAs in adults with ARDS. Current evidence does not support the early routine use of an NMBA infusion in adults with ARDS of any severity. It favours avoiding a continuous infusion of NMBA for patients who are ventilated using a lighter sedation strategy. However, for patients who require deep sedation to facilitate lung protective ventilation or prone positioning, and require neuromuscular blockade, an infusion of an NMBA for 48 h is a reasonable option.
Compared to conventional spectroscopy or chromatography analysis, chemical sensing based on colorimetric changes offers an alternative to monitor potential metal hazards in aqueous environment ...through rapid and low-cost colorimetric changes which can be easily interpreted
In this work poly(ethylene glycol) (PEG 2000) was modified with a carboxylic acid spiropyran (SPCOOH) derivate by Steglich esterification (PEGSP2). PEGSP2 was incorporated into a poly(-caprolactone) (PCL) polymer matrix by electrospinning technique to produce nanofibers with photochromic properties. Spectroscopic analysis, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) were used to characterize PEGSP2. Drop shape analysis (DSA) and scanning electronic microscopy (SEM) were used to characterize the electrospun (ES) nanofibers morphology. Several metal ions solutions relevant to environmental hazards were prepared to be spotted on the surface of ES nanofibers for photochromatic sensing. Among them, Mg
, Ca
, Zn
, Cd
, La
, and Er
demonstrated orange fluorescence when exposed to UV light. ES nanofibers also presented higher wettability when compared to a pure PCL polymer matrix, which is critical for sensitivity. Eighteen metals ions could be detected on the electrospun material. Additionally, among all metal ions Fe
was the most sensitive one in solution, in a µmol L
range.
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