An Intelligent Transportation System to control air pollution and road traffic in cities integrating CEP and Colored Petri Nets

Neural Computing and Applications - Air pollution generated by road traffic in large cities is a great concern in today’s society since pollution has an important impact on human health, even...     

Study of three different families of water-soluble copolymers: synthesis, characterization and viscoelastic behavior of semidilute solutions of polymers prepared by solution polymerization

Polymer chains consisting of water-soluble polyacrylamides, hydrophobically modified with low amounts of N,N-dialkylacrylamides (N,N-dihexylacrylamide (DHAM) and N,N-dioctylacrylamide (DOAM)) have been prepared via free radical solution polymerization, using two hydrophobic initiators derived from 4,4′-azobis(4-cyanopentanoic acid) (ACVA) containing long linear chains of 12 (C12) and 16 (C16) carbon atoms. This procedure resulted in polyacrylamides containing hydrophobic groups along the chain as well as at the chain ends. This class of polymers, termed ‘combined associative polymers’, has been studied and compared with the multisticker (with hydrophobic groups along the polymer chain) and telechelic (with hydrophobic groups at the chain ends) associative polymers, which were prepared with DHAM or DOAM and with the hydrophobic initiator (ACVA) modified with alkyl chains of two different lengths. The viscoelastic properties of these different families of associative polymers were investigated using steady-flow and oscillatory experiments. The effect of type, localization and concentration of the hydrophobic groups on the viscosity of the associative polymer solution was investigated. All viscosity curves clearly show two different regimes within the semidilute range: a first unentangled regime where the viscosity increases moderately; and a second entangled regime where the viscosity varies according to a power law, proportional to C⁴. The relaxation time, T_R, and the plateau modulus, G₀, showed relatively high values which increased with the number of carbon atoms in the hydrophobic groups. The combined associative polymer (PAM-co-DHAM/ACVA12) showed relaxation times that remained relatively constant along the concentrations studied, but very high values of G₀.     

Triacylglycerols and regiospecific fatty acid analyses of philippine seed oils

Three Philippine seed oils, namely coconut (Cocos nucifera Linn.), pilinut (Canarium ovatum Engl.), and cashew (Anacardium occidentale Linn.), which were selected for their local abundance and availability, were examined for their triacylglycerol profiles and fatty acid compositions. Triacylglycerol molecular species in terms of carbon number and partition number were determined by gas chromatography and liquid chromatography, respectively. The distribution of fatty acids in the primary and secondary positions of the glycerol backbones for the three oils were examined by regiospecific analysis by using pancreatic lipase. Coconut oil had high concentrations of lauric and myristic acids, while the other two oils did not have such fatty acids. Lauric acid in coconut oil and linoleic acid in pilinut oil were distributed mainly in the primary positions (sn-1,3) of the glycerol backbone. Trilaurin and dioleylpalmitoylglycerol were the major triglycerides in coconut and pilinut oils, respectively.     

Reversal left diastolic ventriculo-atrial flow induced by asynchronism in a patient with dilated cardiopathy and VVI pacemaker]

Current therapy for glioma is suboptimal. The transfer of apoptosis genes to tumors constitutes one of the most promising strategies for cancer gene therapy. We have previously shown that massive apoptosis occurs when wild-type p53 or E2F-1 expression is induced in glioma. However, the mechanism of action and the efficiency in inducing apoptosis of these two proteins are not similar. Adenovirus-mediated p53 gene transfer is ineffective in causing apoptosis in glioma cells that retain wild-type p53 genotype or overexpress the p21 protein. The p16/Rb/E2F pathway is the most frequent target of genetic alterations in gliomas, and therefore constitutes a suitable target for gene therapy strategies. However, the transfer of either the p16 or Rb gene to glioma cells results in cytostatic effect. The E2F-1 protein is able to induce generalized apoptosis in gliomas independently of the p53, p16 or Rb status. In addition, p21- or p16-mediated growth arrest did not protect glioma cells from E2F-1-mediated apoptosis. The apoptotic molecule bax is induced in p53-mediated apoptosis, but bax is not induced in E2F-1-mediated apoptosis in glioma cells. Careful selection of patients may be necessary before designing therapeutic strategies using either p53 or E2F-1 as a therapeutic tools for glioma patients.     

Parallel solvers for discrete-time algebric Riccati equations

We investigate the numerical solution of discrete-time algebraic Riccati equations on a parallel distributed architecture. Our solvers obtain an initial solution of the Riccati equation via the disc function method, and then refine this solution using Newton's method. The Smith iteration is employed to solve the Stein equation that arises at each step of Newton's method. The numerical experiments on an Intel Pentium-II cluster, connected via a Myrinet switch, report the performance and scalability of the new algorithms. Copyright © 2001 John Wiley & Sons, Ltd.     

Grafting of cyclodextrins onto polypropylene nonwoven fabrics for the manufacture of reactive filters. II. Characterization

A novel method for the preparation of immobilized α, β, or γ‐cyclodextrins on polypropylene nonwoven supports has been previously presented. The obtained new materials were prepared by graft‐polymerization of glycidyl methacrylate onto polypropylene after activation of the support by the electron beam technique, followed by the coupling of cyclodextrins with the epoxide groups. The structure of the resulting materials is characterized in detail using Fourier transform infrared spectroscopy, solid state nuclear magnetic resonance analysis, differential scanning calorimetry, thermogravimetric analysis, and optical microscopy. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2166–2173, 2000     

Peimine,an Anti-Inflammatory Compound from Chinese Herbal Extracts,Modulates Muscle-Type Nicotinic Receptors

Fritillaria bulbs are used in Traditional Chinese Medicine to treat several illnesses. Peimine (Pm), an anti-inflammatory compound from Fritillaria, is known to inhibit some voltage-dependent ion channels and muscarinic receptors, but its interaction with ligand-gated ion channels remains unexplored. We have studied if Pm affects nicotinic acetylcholine receptors (nAChRs), since they play broad functional roles, both in the nervous system and non-neuronal tissues. Muscle-type nAChRs were incorporated to Xenopus oocytes and the action of Pm on the membrane currents elicited by ACh (I_AChs) was assessed. Functional studies were combined with virtual docking and molecular dynamics assays. Co-application of ACh and Pm reversibly blocked I_ACh, with an IC₅₀ in the low micromolar range. Pm inhibited nAChR by: (i) open-channel blockade, evidenced by the voltage-dependent inhibition of I_Ach, (ii) enhancement of nAChR desensitization, revealed by both an accelerated I_ACh decay and a decelerated I_ACh deactivation, and (iii) resting-nAChR blockade, deduced from the I_ACh inhibition elicited by Pm when applied before ACh superfusion. In good concordance, virtual docking and molecular dynamics assays demonstrated that Pm binds to different sites at the nAChR, mostly at the transmembrane domain. Thus, Pm from Fritillaria bulbs, considered therapeutic herbs, targets nAChRs with high affinity, which might account for its anti-inflammatory actions.     

Volume-Independent Sodium Toxicity in Peritoneal Dialysis: New Insights from Bench to Bed

Sodium overload is common in end-stage kidney disease (ESKD) and is associated with increased cardiovascular mortality that is traditionally considered a result of extracellular volume expansion. Recently, sodium storage was detected by Na23 magnetic resonance imaging in the interstitial tissue of the skin and other tissues. This amount of sodium is osmotically active, regulated by immune cells and the lymphatic system, escapes renal control, and, more importantly, is associated with salt-sensitive hypertension. In chronic kidney disease, the interstitial sodium storage increases as the glomerular filtration rate declines and is related to cardiovascular damage, regardless of the fluid overload. This sodium accumulation in the interstitial tissues becomes more significant in ESKD, especially in older and African American patients. The possible negative effects of interstitial sodium are still under study, though a higher sodium intake might induce abnormal structural and functional changes in the peritoneal wall. Interestingly, sodium stored in the interstial tissue is not unmodifiable, since it is removable by dialysis. Nevertheless, the sodium removal by peritoneal dialysis (PD) remains challenging, and new PD solutions are desirable. In this narrative review, we carried out an update on the pathophysiological mechanisms of volume-independent sodium toxicity and possible future strategies to improve sodium removal by PD.     

An electrochemical bioassay for dichlorvos analysis in durum wheat samples

The use of an acetylcholinesterase inhibition assay for the detection of dichlorvos in durum wheat samples by a simplified extraction procedure is reported. After an incubation step, the residual activity was determined with an amperometric biosensor using a portable potentiostat. The use of electric eel and recombinant acetylcholinesterase was compared. The effect of the matrix extract was evaluated by using various sample:solvent ratios, 1:2.5, 1:5, 1:10, and 1:20. The optimal extraction ratio, considering the electrochemical interferences and the effect on enzyme activity and bioavailability of the pesticide, was 1:10. Calibrations were performed in buffer and durum wheat extract. The calculated detection limits in buffer solution were 10 ng/ ml and 0.045 ng/ml for electric eel and recombinant acetylcholinesterase, respectively, whereas operating in the matrix extract they increased up to 45 ng/ml and 0.07 ng/ml, corresponding to 0.45 mg/kg (extraction ratio 1:10) and 0.07 mg/kg in samples. These characteristics allowed the detection of contaminated samples at the maximum residue limit, which is 2 mg/kg and well below. Fortified samples of durum wheat were obtained with both dichlorvos and the commercial product Didivane, which contains dichlorvos as an active molecule. At all the tested levels, the occurrence of contaminant was detected with an average recovery of 75%. The total assay time, including the extraction step, was 30 min. Because several extractions as well as most of the assay steps can be run simultaneously, the throughput for one operator is 12 determinations per hour.     

Tailoring the synthesis of stainless steel wire mesh-supported ZnO

The aim of this work was to synthesise different nanostructures of zinc oxide supported on a stainless steel wire mesh, using hydrothermal processes in which several conditions were applied. The effect of the different synthesis parameters on the final properties of the samples (yield and geometrical dimensions) were analysed and discussed. The ZnO nanomaterials obtained exhibit a homogeneous distribution over the metallic wire mesh, with mass yields in the range of 3–30 wt.%, a prismatic morphology with a hexagonal cross-section, lengths between 700 nm and 6 μm and widths in the 70 nm–2.3 μm range. These nanomaterials are intended to be applied in photocatalytic reactions and as catalyst supports.