Ethanolics extracts of Moringa

The use of natural antioxidants has been widely promoted in the food industry, because it is economically viable and very attractive with consumers. In this study, we determined the extractable total phenolic content (FET) of crude ethanol extracts of the leaves (EL), flowers, and seed pods of Moringa oleifera Lam. We also evaluated the antioxidant effect of the extracts on oxidative stability of soybean oil, through the accelerated PDSC and Rancimat^® techniques using the synthetic antioxidants butylated hydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ) as positive control. The values of FET in the extracts ranged from 41.75 ± 3.35 to 53.69 ± 1.00 mg GAE g^?1, and EL extract exhibited best result. The results of oxidative stability in both techniques showed that the EL extract provided greater protection to the oil, indicating a correlation between the amount of FET and the protective effect. Comparison made between the synthetic antioxidants and extracts revealed that in the Rancimat technique, extracts were less effective than the synthetic antioxidants TBHQ and BHT, however, in the PDSC technique the EL extract was more effective than BHT, proving to be a good alternative for applications in the soybean oil, replacing this synthetic antioxidant.     

Determination of 3‐α‐hydroxytibolone in human plasma by LC‐MS/MS: application for a pharmacokinetic study after administration of a tibolone formulation

A new method was developed for the quantitation of 3‐α‐hydroxy tibolone, in human plasma, after oral administration of a tablet formulation containing tibolone (2.5 mg). 3‐α‐Hydroxy tibolone was extracted by a liquid–liquid procedure, using cyproterone acetate as internal standard and chlorobutane as extraction solvent. After extraction, samples were submitted to a derivatization step with p‐toluenesulfonyl isocyanate. A mobile phase consisting of acetonitrile and water (72:28 v/v) was used and chromatographic separation was achieved using Agilent XDB C₁₈ column (100 × 4.6 mm i.d.; 5 µm particle size), at 40°C. Mass spectrometric detection was performed using atmospheric pressure chemical ionization in negative mode for 3‐α‐hydroxy tibolone and in positive mode for cyproterone acetate. The fragmentation transitions were m/z 510.2 → m/z 170.1 and m/z 417.0 → m/z 357.1 for 3‐α‐hydroxy tibolone and cyproterone acetate, respectively. Calibration curves were constructed over the range 100–30,000 pg/mL and the method was shown to be specific, precise and accurate, with a mean recovery rate of 94.2% for 3‐α‐hydroxy tibolone. No matrix effect or carry‐over was detected in the samples. The validated method was applied in a pharmacokinetic study with a tibolone formulation in healthy female volunteers. Copyright © 2013 John Wiley & Sons, Ltd.     

Friction properties of moulding thermoplastics

 During the ejection phase of the injection moulding cycle the parts are mechanically forced to separate from the moulding surfaces, this aspect being more relevant with deep cores. The design of the ejection system depends on factors such as the draft angles, the surface finish, and the properties of the moulding material at the ejection temperature and the dimensioning of actuation devices (e.g., hydraulic or pneumatic cylinders). Knowledge of the friction properties of the mating metal and plastics surfaces is important to optimize the ejection system. The coefficient of friction at the ejection stage depends on the surface texture of the core and the temperature at ejection.

This paper reviews recent research on the static coefficient of friction in moulding conditions. It also reviews results obtained with a prototype apparatus that reproduces the conditions occurring during the ejection phase.     

Treatment of sulcus vocalis: Auditory perceptual and acoustical analysis of the slicing mucosa surgical technique

Sulcus vocalis is a furrow in the mucosa of the vocal folds that causes glottic insufficiency, irregular vibrations, and a distinctive dysphonia of variable severity. Treatment of sulcus vocalis needs to achieve anatomical and functional improvements that satisfy the behavior of the larynx and vocal quality. We suggest a combined approach, which includes vocal fold mucosal surgery through a technique called slicing mucosa, followed by intensive vocal rehabilitation. The aim of the surgery is to detach the mucosa of the sulcus and to interrupt the longitudinal fibrotic tension lines. The results of this procedure in 10 patients were analyzed through visual, auditory, and acoustical methods, and the data lead us to conclude that the treatment proposed offered a good anatomical result, a better vibratory pattern, and an improvement in overall vocal quality.     

Low‐Level Laser Therapy and Sodium Diclofenac in Acute Inflammatory Response Induced by Skeletal Muscle Trauma: Effects in Muscle Morphology and mRNA Gene Expression of Inflammatory Markers

Pharmacological therapy is widely used in the treatment of muscle injuries. On the other hand, low‐level laser therapy (LLLT) arises as a promising nonpharmacological treatment. The aim of this study was to analyze the effects of sodium diclofenac (topical application) and LLLT on morphological aspects and gene expression of biochemical inflammatory markers. We performed a single trauma in tibialis anterior muscle of rats. After 1 h, animals were treated with sodium diclofenac (11.6 mg g^‐1 of solution) or LLLT (810 nm; continuous mode; 100 mW; 3.57 W cm^?2; 1, 3 or 9 J; 10, 30 or 90 s). Histological analysis and quantification of gene expression (real‐time polymerase chain reaction—RT‐PCR) of cyclooxygenase 1 and 2 (COX‐1 and COX‐2) and tumor necrosis factor‐alpha (TNF‐α) were performed at 6, 12 and 24 h after trauma. LLLT with all doses improved morphological aspects of muscle tissue, showing better results than injury and diclofenac groups. All LLLT doses also decreased (P < 0.05) COX‐2 compared to injury group at all time points, and to diclofenac group at 24 h after trauma. In addition, LLLT decreased (P < 0.05) TNF‐α compared both to injury and diclofenac groups at all time points. LLLT mainly with dose of 9 J is better than topical application of diclofenac in acute inflammation after muscle trauma.     

1,1-Diamino-2-nitroethylenes as excellent hydrogen bond donor organocatalysts in the Michael addition of carbon-based nucleophiles to β-nitrostyrenes

A new class of hydrogen bond donor catalysts based on the 1,1-diamino-2-nitroethylene scaffold has been introduced for the activation of trans-β-nitrostyrenes toward reactions with a range of carbon-based nucleophiles, affording the corresponding adducts in excellent yields. Importantly, this new set of organocatalysts is easily prepared from commercially available starting materials in mild reaction conditions.     

Adsorption of benzene-1,4-dithiol on the Au(111) surface and its possible role in molecular conductance

It is a consensus in the field of molecular electronics that the transport of charge across a single molecule depends sensitively on the details of the interaction between the molecule and the metallic leads, such as the molecular orientation. To advance the design of complex molecular devices, it is crucial to have a detailed understanding of these many aspects that influence the electron transport. A simple system that has been used as a paradigm of the class of conjugated aryl molecules is the benzene-1,4-dithiol (BDT). However, we still do not have a full understanding of the BDT transport experiments. Usually the geometries considered in transport calculations assumed that the BDT was connected to the two Au leads via the S atoms, and that the molecule was either perpendicular or close to a perpendicular configuration relative to the Au surfaces. Using ab initio calculations, we show that, for an isolated molecule, the configuration with largest adsorption energy has the BDT phenyl ring closer to being parallel to the surface, and we then argue, based on nonequilibrium Green's function-density functional theory calculations, that, depending on the experimental procedure, this may be the relevant configuration to be used in the transport calculations.     

Photon stimulated ion desorption studies from poly(sulphone) using synchrotron radiation in a single-bunch mode

Photon stimulated ion desorption (PSID) studies from poly(sulphone) (PS) have been carried out by using high-resolution time-of-flight mass spectrometry. Synchrotron radiation at the Brazilian Synchrotron Light Source (LNLS) operating in a single-bunch mode was used as excitation source. PS was excited at the sulphur 1s-edge and the desorption of small and large fragments has been observed. The results are discussed in terms of the X-ray induced electron stimulated desorption mechanism. The present results contrast with previous ones reported for poly(3-methylthiophene) (PMeT), in which the observation of S⁺ and S²⁺ was interpreted solely in terms of an Auger-stimulated ion desorption mechanism.