Automatic detection of surface EMG activation timing using a wavelet transform based method

The problem of the identification of the muscle contraction timing by using surface electromyographic signal is addressed. The timing detection of the muscular activation in dynamic conditions has a real clinical diagnostic impact. Widely used single threshold methods still rely on the experience of the operator in manually setting that threshold. A new approach to detect the muscular activation intervals, that is based on discontinuities detection in the wavelet domain, is proposed. Accuracy and precision of the algorithm were assessed by using a set of simulated signals obtaining values lower than 11.0 and 8.7 ms for biases and standard deviations of the estimation, respectively. Moreover an experimental application of the algorithm was carried out recruiting a population of 10 able-bodied subjects and processing the myoelectric signals recorded from the lower limb during an isokinetic exercise. The algorithm was able to reveal correctly the timing of muscular activation with performance comparable to the state-of-the-art methods. The detection algorithm is automatic and user-independent, it manages the detection of both onset and offset activation, it can be fruitfully applied even in presence of noise and, therefore, it can be used also by unskilled operators.     

UDP-GlC:glycoprotein glucosyltransferase-glucosidase II,the ying-yang of the ER quality control

The N-glycan-dependent quality control of glycoprotein folding prevents endoplasmic to Golgi exit of folding intermediates, irreparably misfolded glycoproteins and incompletely assembled multimeric complexes. It also enhances folding efficiency by preventing aggregation and facilitating formation of proper disulfide bonds. The control mechanism essentially involves four components, resident lectin-chaperones that recognize monoglucosylated polymannose glycans, a lectin-associated oxidoreductase acting on monoglucosylated glycoproteins, a glucosyltransferase that creates monoglucosytlated epitopes in protein-linked glycans and a glucosidase that removes the glucose units added by the glucosyltransferase. This last enzyme is the only mechanism component sensing glycoprotein conformations as it creates monoglucosylated glycans exclusively in not properly folded species or in not completely assembled complexes. The glucosidase is a dimeric heterodimer composed of a catalytic subunit and an additional one that is partially responsible for the ER localization of the enzyme and for the enhancement of the deglucosylation rate as its mannose 6-phosphate receptor homologous domain presents the substrate to the catalytic site. This review deals with our present knowledge on the glucosyltransferase and the glucosidase.     

Carbonic anhydrase inhibitors. Antioxidant polyphenols effectively inhibit mammalian isoforms I–XV

A series of polyphenolic derivatives, including resveratrol, dobutamine, curcumin, catechin and silymarine were investigated for the inhibition of all the catalytically active mammalian isozymes of the metalloprotein carbonic anhydrase (CA, EC 4.2.1.1), that is, CA I–CA XV. These polyphenols effectively inhibited CAs, with K_Is in the range of 380 nM–12.02 μM. The various isozymes showed quite diverse inhibition profiles with these compounds, which possess scaffolds not present in other investigated CA inhibitors (CAIs). These data may lead to drug design campaigns of effective CAIs possessing a diverse inhibition mechanism compared to sulfonamide/sulfamate inhibitors, based on such less investigated scaffolds.     

A Survey of Phytotoxic Microbial and Plant Metabolites as Potential Natural Products for Pest Management

Phytotoxic microbial metabolites produced by certain phytopathogenic fungi and bacteria, and a group of phytotoxic plant metabolites including Amaryllidacea alkaloids and some derivatives of these compounds were evaluated for algicide, bactericide, insecticide, fungicide, and herbicide activities in order to discover natural compounds for potential use in the management and control of several important agricultural and household structural pests. Among the various compounds evaluated: i) ophiobolin A was found to be the most promising for potential use as a selective algicide; ii) ungeremine was discovered to be bactericidal against certain species of fish pathogenic bacteria; iii) cycasin caused significant mortality in termites; iv) cavoxin, ophiobolin A, and sphaeropsidin A were most active towards species of plant pathogenic fungi; and v) lycorine and some of its analogues (1‐O‐acetyllycorine and lycorine chlorohydrate) were highly phytotoxic in the herbicide bioassay. Our results further demonstrated that plants and microbes can provide a diverse and natural source of compounds with potential use as pesticides.     

Fluorescence emission and enhanced photochemical stability of Zn-5-triethyl ammonium methyl salicylidene ortho-phenylendiiminate interacting with native DNA

The photophysical and photochemical properties of the cationic Zn^II complex of 5-triethyl ammonium methyl salicylidene ortho-phenylendiimine (ZnL²⁺) interacting with native DNA were investigated by steady state and time-resolved fluorescence spectroscopies. Experimental results indicate that, in the presence of DNA, ZnL²⁺ is efficiently protected from a photochemical process, which occurs when it is in the free state dispersed in aqueous solution. The analysis of the absorption and emission spectra of ZnL²⁺, both stored in the dark and after exposure to tungsten lamp light for 24 h, corroborated by quantum chemical calculations, allowed us to point out that ZnL²⁺ undergoes a photoinduced two-electron oxidation process. According to this picture, the protective action of DNA toward the intercalated ZnL²⁺ was attributed to an effective inhibition of the ZnL²⁺ photooxidation. In this context, it can be considered that DNA-intercalated ZnL²⁺ is located in a region more hydrophobic than that sensed in the bulk water solvent. Moreover, by a thorough analysis of steady state and time-resolved fluorescence spectra, the interaction process can be consistently explained in terms of a complete intercalation of the complex molecules and that the polarity of the environment sensed by intercalated ZnL²⁺ is comprised between that of methanol and ethanol.     

Proteomics and transcriptomics investigation on longissimus muscles in Large White and Casertana pig breeds

Consumer complaints against the blandness of modern lean meat and the frequent reference to the more strongly flavored meat that was available years ago have prompted reconsideration of high fat-depositing typical pig breeds. Casertana and Large White pig breeds are characterized by a different tendency toward fat accumulation as they exhibit opposite genetic and physiological traits with respect to the energy metabolism. These physiological differences were investigated in longissimus lumborum muscles through proteomics (2-DE, MS/MS) and microarray approaches. Data were analyzed for pathway and network analyses, as well as GO term enrichment of biological functions. As a result, Casertana showed a greater amount of proteins involved in glycolitic metabolism and mainly rely on fast-mobilizable energy sources. Large White overexpressed cell cycle and skeletal muscle growth related genes. Metabolic behavior and other implications are discussed.