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•Microwave radiation was successfully applied for crude oil demulsification.•Multimode microwave radiation provided faster heating.•Single mode microwave radiation spent less ...energy.•Total applied energy rules the demulsification efficiency.
During petroleum production and refining, water-in-crude oil emulsions are formed in a desirable or undesirable fashion. However, for economic and operational reasons it is necessary to separate water from oil. In order to present an alternative to the currently available techniques used to solve such task, this study aims to analyze the influence of microwave application modes (multimode and single mode) on the breaking efficiency of a synthetic water-in-crude oil emulsion. In both heating modes, it was observed that the water content, temperature, and total applied energy are preponderant parameters regarding obtain higher efficiencies. The single mode heating required less energy to reach the same temperature and/or demulsification efficiency while the multimode provided better reproducibility. The power dissipation and, consequently, the microwave heating efficiency was dependent on the heating temperature and the emulsion water content. Furthermore, it was noticed that the presence of chemical additives tends to minimize any effect of irradiation mode on demulsification efficiency at temperatures above the 120°C.
In this work, low soluble supramolecular complex between the losartan potassium (Los) and hydroxypropil-β-cyclodextrin (HPβCD) were characterized throughout phase-solubility, NMR techniques (1H and ...2D-ROESY) and isothermal titration calorimetry (ITC) in order to attain physical–chemical knowledge of the system. In addition, the hypertensive effect of composition Los/HPβCD was evaluated aiming to obtain a more efficient oral pharmaceutical composition. ESI mass spectrometry and ITC blank experiment demonstrate the presence of Los clusters at 30mM pure solution. Phase-solubility experiments showed a “Bs” type system, due to the formation of a less soluble complex than pure Los. NMR demonstrated the short distance interactions between the Los and the cyclodextrin, where several possibilities of interactions were observed. ITC data suggest an average 1:1 stoichiometry of Los and the cyclodextrin. The complex demonstrated efficiency in hypertension control, presenting antagonist action on the pressure effect of angiotensin II within 30h, as compared to Los alone, 6h, indicating that inclusion of Los in HPβCD enhanced the extent and duration of its antagonistic action. In this work, a model of interaction between Los and HPβCD was proposed based on dissociation of self-assembled Los followed by complexation with HPβCD.
Losartan (Los), a non-peptidic orally active agent, reduces arterial pressure through specific and selective blockade of angiotensin II receptor AT1. However, this widely used AT1 antagonist presents ...low bioavailability and needs once or twice a day dosage. In order to improve its bioavailability, we used the host: guest strategy based on β-cyclodextrin (βCD). The results suggest that Los included in βCD showed a typical pulsatile release pattern after oral administration to rats, with increasing the levels of plasma of Los. In addition, the inclusion compound presented oral efficacy for 72 h, in contrast to Los alone, which shows antagonist effect for only 6 h. In transgenic (mREN2)L27 rats, the Los/βCD complex reduced blood pressure for about 6 d, whereas Los alone reduced blood pressure for only 2 d. More importantly, using this host: guest strategy, sustained release of Los for over a week via the oral route can be achieved without the need for encapsulation in a polymeric carrier. The proposed preformulation increased the efficacy reducing the dose or spacing between each dose intake.
Aprotic ionic liquids (C4pyr+NTf2-, C8mim+NTf2-, C8mim+OTf-, C8mim+PF6-, C8mim+BF4-, C12mim+NTf2-, and C12mim+Cl-) were successfully evaluated as viscosity modifiers, emulsion inhibitors, and ...demulsifiers. They are prone to be applied for the heavy oil production since such crude oil type potentializes some issues that are typically observed in the petroleum industry. Among them, it is worth highlighting the low flowability due to the oil's high viscosity. Also, high-viscous crude oil usually generates stable emulsions since they have high resins and asphaltene contents, which are interfacial-active. Thus, for operational and economic reasons there is a need for technologies that facilitate the improvement of the heavy-oil flowability as well as the demulsification process. Then, this work aimed to analyze the influence of the ionic liquid chemical structure (cationic alkyl length, cationic functional group, and anion type) upon the oil viscosity, emulsion inhibition or demulsification, at concentrations of 5 and 100 ppm (m/m). Two Brazilian heavy-oils were used for this study. Viscosity measurements of these oils at room temperature (25 °C) were made by an oscillatory rheometer before and after the addition of ionic liquid. Also, the emulsification inhibition and demulsification efficiency were analyzed by centrifugation. The results showed that the 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide promoted a demulsification efficiency higher than 99%. In turn, the 1-butylpyridinium bis(trifluoromethylsulfonyl)-imide was the one that worked as an emulsion inhibitor. On the other hand, the interaction between the studied oils and some of the used ionic liquids enhanced the oil viscosity. All the evidence points out to the fact that it was caused by the asphaltene aggregation due to the formation of an ionic liquid-asphaltene molecular structure. The observed viscosity increase was of 11% for oil A and 7% for the oil B.
Phytogenic additives are organic molecules that also improve ruminal fermentation, turning the supplemented individuals into more productive animals, without damage the population welfare. The ...objective of this study was to evaluate the effects of mesquite (Prosopis julifora Sw. DC.) extract as phytogenic additive for sheep finished on pasture in the Brazilian Northeast semiarid region. Twenty-four intact lambs (Santa Ines * Dorper F.sub.1 crossbred) were used, with an initial body weight of 23.00 + or - 1.83 kg. The experiment was carried out in a complete randomized design with four treatments and six replicates. Treatments consisted of four diets: Pasture and no supplementation; grazing pasture and phytogenic additive; pasture, supplementation with Tifton 85 hay, and concentrate; and pasture, phytogenic additive, and supplementation with Tifton 85 hay and concentrate. Prior to supplementation, animals received the phytogenic additive according to treatment. There were nonsignificant differences for nutrient intake and behavior patterns (P > 0.05). However, additive intake derived from mesquite provided an increase (P < 0.05) in digestibility (14.40% total digestible nutrients), N balance (27.12% retained N:ingested N) and performance (8.82% final body weight, 21.81% total weight gain, and 30.81% average daily gain) compared to animals consuming only pasture in rainy period. Thus, the use of mesquite extract as phytogenic additive is recommended for sheep finished on pasture in the Brazilian semiarid region. Key words: Bioactive compounds, caatinga, digestibility of nutrients, intake, tannins.
Highlights • Red laser (660 nm) showed no cytotoxicity in A431 cells. • Methylene blue showed a cytotoxicity dose dependent. • Sub-additive cytotoxic effect between photodynamic therapy and erlotinib.
This work describes chemical properties and anti-hypertensive activity of an oral pharmaceutical formulation obtained from the complexation of β-cyclodextrin (β-CD) with bradykinin potentiating penta ...peptide (BPP-5a) founded in the
Bothrops jararaca poison. Physical chemistry characterizations were recorded in order to investigate the intermolecular interactions between species in complex. Circular dichroism data indicated conformational changes of BPP-5a upon complexation with β-CD. ROESY and theoretical calculations showed a selective approximation of triptophan moiety into cavity of β-CD. Isothermal titration calorimetry data indicated an exothermic formation of the complex, which is accomplished by reduction of entropy. The anti-hypertensive activity of the BPP-5a/β-CD complex has been evaluated in spontaneous hypertensive rats, showing better results than pure BPP-5a.
Ibuprofen‐intercalated layered double hydroxides (LDH‐IBU) have been successfully synthesized via a coprecipitation method with a nominal Al3+/Mg2+ ratio of 0.5 and a variable molar IBU/(Al3++Mg2+) ...ratio of 0, 0.15, 0.18, 0.24, 0.36, and 0.72. After an accurate determination of the composition, the nature of the intercalated species and the effective intercalation yield from NO3− to IBU, it is shown that the synthesis route used allows a good control of the quantity of intercalated IBU within the LDH framework. This results in different samples with full or partial IBU intercalation in the interlayer space in exchange of nitrate anions. The analysis of the X‐ray diffraction basal reflections reveals that the intercalation of IBU in the framework only increases the basal distances with no alteration of the brucite‐type layers. Also, a computational study used to model the positions and shapes of the basal reflections showed that the structure of the nonfully intercalated compounds follows a random interstratification scheme. Finally, three samples ranging from slightly to fully IBU‐intercalated galleries were selected for preliminary in vivo assays. These tests showed a strong tendency that after 24 hours the low yield of IBU‐intercalated compounds are almost as efficient as the fully intercalated sample.
Summary
Background
There is evidence that adenosine plays a role in the pathogenesis of asthma and rhinitis; however, it is currently unclear whether adenosine receptors are useful therapeutic ...targets in the treatment of allergic airway diseases.
Objective
The study evaluated the efficacy of intranasal treatment with an adenosine A2A receptor agonist/adenosine A3 receptor antagonist (50 μg), administered twice daily for 7 days, to reduce nasal symptoms and release of inflammatory mediators following intranasal allergen challenge in patients with allergic rhinitis (AR). The compound was compared with twice‐daily treatment with intranasal fluticasone proprionate nasal spray (FPANS) for 7 days.
Methods
A randomized, double‐blind, double‐dummy, placebo‐controlled, three‐way balanced, incomplete block, crossover study was conducted on 48 males with verified AR. Following intranasal challenge with either an extract from the house dust mite (HDM), Dermatophagoides pteronyssinus, rye grass or cat dander, nasal responses and the concentrations of albumin, tryptase, myeloperoxidase, eosinophilic cationic protein, epithelial neutrophil‐activating protein‐78 (ENA‐78), IL‐5 and IL‐8 in nasal secretions were measured and treatment groups were compared.
Results
Drug improved nasal blockage but had no significant effect on rhinorrhoea, number of sneezes or peak nasal inspiratory flow measurements when compared with placebo. Drug reduced tryptase release after EAR but did not significantly reduce the levels of other mediators.
Conclusion
A novel agonist/antagonist of adenosine A2A and A3 receptors appears to have limited clinical benefit in both the early‐phase and the late‐phase response to intranasal allergen challenge. However, reduction of some pro‐inflammatory mediators suggests that comparable, more selective compounds may have additional benefits meriting further investigation.
Angiotensin (Ang)-(1-7), acting through the Mas receptor, opposes the actions of Ang II. Molecular mechanisms for this are unclear. Here we sought to determine whether Ang-(1-7) influences Ang II ...signaling in human endothelial cells, focusing specifically on Src homology 2-containing inositol phosphatase 2 (SHP-2) and its interaction with c-Src. Ang II–induced phosphorylation of c-Src, extracellular signal regulated kinase (ERK)1/2, and SHP-2 and activation of NAD(P)H oxidase were assessed in the absence and presence of Ang-(1-7) (10 mol/L, 15 minutes) by immunoblotting and lucigenin-enhanced chemiluminescence, respectively. (D-Ala)-Ang I/II (1-7) (Ang fragment 1-7 receptor antagonist) was used to block Ang-(1-7) effects. Association between SHP-2 and c-Src was assessed by immunoprecipitation/immunoblotting studies. Ang II significantly increased activation of c-Src, ERK1/2, and NAD(P)H oxidase and reduced phosphorylation of SHP-2 (P<0.05) in human endothelial cells. These effects were abrogated in cells pre-exposed to Ang-(1-7). Ang fragment 1-7 receptor antagonist pretreatment blocked the negative modulatory actions of Ang-(1-7) on Ang II–induced signaling. Ang-(1-7) alone did not significantly alter phosphorylation of c-Src, ERK1/2, and SHP-2 and had no effect on basal activity of NAD(P)H oxidase. SHP-2 and c-Src were physically associated in the basal state. This association was increased by Ang-(1-7) and blocked by Ang fragment 1-7 receptor antagonist. Our findings demonstrate that, in human endothelial cells, Ang-(1-7) negatively modulates Ang II/Ang II type 1 receptor–activated c-Src and its downstream targets ERK1/2 and NAD(P)H oxidase. We also show that SHP-2-c-Src interaction is enhanced by Ang-(1-7). These phenomena may represent a protective mechanism in the endothelium whereby potentially deleterious effects of Ang II are counterregulated by Ang-(1-7).
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