An in vitro controlled release study of valproic acid encapsulated in a titania ceramic matrix

Despite the therapeutic efficacy of valproic acid towards numerous diseases, its poor bioavailability and systemic side effects pose significant barriers to long term treatment. In order to take advantage of controlled release implants of valproic acid, the drug was encapsulated into titania ceramic matrices via a sol-gel process. The integrity and structure of valproic acid-containing matrices were characterized through the use of FESEM, TEM, and BET analyses. In vitro controlled release studies and kinetic analyses were performed under ambient conditions (25 °C, atmospheric pressure) and controlled release behaviors were studied using a GC-MS method. Results showed first order dependence in the rate of valproic acid release as a function of drug concentrations in the titania ceramic device. A marked dependence on the surface area and pore size distribution with drug loading was also observed. This research opens new possibilities for the design of novel time-delayed controlled release systems for valproic acid encapsulates.     

Novel design model for the stator currents subsystem of induction motors

The stator currents subsystem is a vital element of many high-performance induction motor control schemes. While there are several control techniques available for this subsystem, traditional linear controllers are still widely used because of its simplicity and proven effectiveness. However, the traditional simplified design-model lacks important information, necessary for the design of high-performance and robust controllers. In this article a novel design-model intended for linear controller formulation and evaluation is developed. This new mathematical representation captures several elements which are missing in the traditional representation, maintaining at the same time a similar level of simplicity. Along the derivation of this new representation several models of decreasing complexity and comprehensiveness are also presented together with a critical classification. This classification is intended to aid the designer in choosing the appropriate mathematical representation for specific purposes. Finally, the article is accompanied with experimental findings which illustrate the use of the proposed model.     

Real plane algebraic curves

We study real algebraic plane curves, at an elementary level, using as little algebra as possible. Both cases, affine and projective, are addressed. A real curve is infinite, finite or empty according to the fact that a minimal polynomial for the curve is indefinite, semi-definite nondefinite or definite. We present a discussion about isolated points. By means of the P operator, these points can be easily identified for curves defined by minimal polynomials of order bigger than one. We also discuss the conditions that a curve must satisfy in order to have a minimal polynomial. Finally, we list the most relevant topological properties of affine and projective, complex and real plane algebraic curves.     

The application of multiplexed,multi‐dimensional ultra‐high‐performance liquid chromatography/tandem mass spectrometry to the high‐throughput screening of lysosomal storage disorders in newborn dried bloodspots

Lysozomal storage disorders are just beginning to be routinely screened using enzyme activity assays involving dried blood spots and tandem mass spectrometry (MS/MS). This paper discusses some of the analytical challenges associated with published assays including complex sample preparation and potential interference from excess residual substrate. Solutions to these challenges are presented in the form of on‐line two‐dimensional chromatography to eliminate off‐line liquid‐liquid extraction (LLE) and solid‐phase extraction (SPE), the use of ultra‐high‐performance liquid chromatography (UHPLC) to separate excess substrate from all other analytes and multiplexed sample introduction for higher throughput required of a population screening assay. High sensitivity, specificity and throughput were demonstrated using this novel method. Copyright © 2010 John Wiley & Sons, Ltd.     

ior egf/r3: A murine monoclonal antibody for diagnostic of epithelial tumors

Monoclonal antibody ior egf/r3 is a IgG2a, recognizes the epidermal growth factor receptor. The aim of the present work was to evaluate the diagnostic efficacy of the^99mTc-labeled ior egf/r3 for the detection of epithelial tumors, its metastasis and its recurrences. The sensitivity by organs was: brain 100%, diegestive tract 90%, head and neck 89%, lung 84% and breast 79%. The overall sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the immunoscintigraphic imaging were 84.1%, 100%, 86.5%, 100% and 52.4%, respectively. Immunoscintigraphy with^99mTc-ior egf/r3 is useful for the diagnosis and follow-up of epithelial tumors.     

Reversibly Switchable Fluorescent Molecular Systems Based on Metallacarborane–Perylenediimide Conjugates

Icosahedral metallacarboranes are θ-shaped anionic molecules in which two icosahedra share one vertex that is a metal center. The most remarkable of these compounds is the anionic cobalt-based metallacarborane [Co(C₂B₉H₁₁)₂]⁻, whose oxidation-reduction processes occur via an outer sphere electron process. This, along with its low density negative charge, makes [Co(C₂B₉H₁₁)₂]⁻ very appealing to participate in electron-transfer processes. In this work, [Co(C₂B₉H₁₁)₂]⁻ is tethered to a perylenediimide dye to produce the first examples of switchable luminescent molecules and materials based on metallacarboranes. In particular, the electronic communication of [Co(C₂B₉H₁₁)₂]⁻ with the appended chromophore unit in these compounds can be regulated upon application of redox stimuli, which allows the reversible modulation of the emitted fluorescence. As such, they behave as electrochemically-controlled fluorescent molecular switches in solution, which surpass the performance of previous systems based on conjugates of perylendiimides with ferrocene. Remarkably, they can form gels by treatment with appropriate mixtures of organic solvents, which result from the self-assembly of the cobaltabisdicarbollide-perylendiimide conjugates into 1D nanostructures. The interplay between dye π-stacking and metallacarborane electronic and steric interactions ultimately governs the supramolecular arrangement in these materials, which for one of the compounds prepared allows preserving the luminescent behavior in the gel state.     

Immobilized ruthenium complexes and aspects of their reactivity

Methodologies for the immobilization and characterization of ruthenium complexes into/onto functionalized silica gel, zeolites, polymers, dendrimers, sol–gel, nano and microparticles are described. The corresponding spectroscopic, electrochemical, and photochemical properties as well as chemical reactivities are used for their characterization and study. Comparison between the reactivities of immobilized and in solution species is presented. Some biological applications are also described.     

Determination of the mineral composition of fresh bovine milk from the milk-producing areas located in the State of Sergipe in Brazil and evaluation employing exploratory analysis

In this work, the mineral composition of fresh bovine milk obtained from the milk-producing areas of the Brazilian State of Sergipe was examined. A dry-ashed digestion method and the ICP OES technique were used for the quantification of mineral elements (e.g., Ca, Mg, K, Na, P, Sr and Zn) in 27 samples of milk collected from properties located in milk-producing areas around Nossa Senhora da Glória. The following ranges of values (% m/v) were obtained: 0.063 to 0.117 for Ca; 0.060 to 0.114 for P; 0.024 to 0.064 for Na; and 0.087 to 0.164 for K. The ranges of values (mg L^− 1) for the other mineral elements were also found: 0.68 to 1.89 for Sr; 2.46 to 5.73 for Zn; and 54.2 to 109.9 for Mg. Additionally, the exploratory evaluation of the 27 milk samples was performed using principal component analysis (PCA) involving seven variables dealing with the effect of different management systems (conventional and organic) on milk composition. The results show that there are indeed differences between the mineral composition of milk from properties that use organic practices and those that use conventional management practices.     

Negishi cross-coupling of organotellurium compounds: synthesis of biaryls, aryl-, and diaryl acetylenes

A functional group tolerant palladium-catalyzed Negishi coupling of diaryl tellurides with organozinc has been developed. This methodology permits efficient preparation of biaryls, aryl acetylenes and diaryl acetylenes in moderate to good yields. A preliminary study to gain further insight into the reaction was performed using in situ ReactIR technology.