An Overview of Analytical Methods to Determine Pharmaceutical Active Compounds in Aquatic Organisms

There is increasing scientific evidence that some pharmaceuticals are present in the marine ecosystems at concentrations that may cause adverse effects on the organisms that inhabit them. At present, there is still very little scientific literature on the (bio)accumulation of these compounds in different species, let alone on the relationship between the presence of these compounds and the adverse effects they produce. However, attempts have been made to optimize and validate analytical methods for the determination of residues of pharmaceuticals in marine biota by studying the stages of sample treatment, sample clean-up and subsequent analysis. The proposed bibliographic review includes a summary of the most commonly techniques, and its analytical features, proposed to determine pharmaceutical compounds in aquatic organisms at different levels of the trophic chain in the last 10 years.     

Synthesis of Polycyclic Aromatic Hydrocarbons Decorated by Fluorinated Carbon Acids/Carbanions

The carboarylation reaction of biphenyl-alkynes was successfully triggered by electrophilic attack of 1,1-bis(triflyl)ethylene on the alkyne moiety to give polycyclic aromatic hydrocarbons (PAHs) decorated by superacidic carbon acid functionality. Neutralisation of thus obtained acids with NaHCO₃ yielded the corresponding sodium salts, which showed improved solubility in both aqueous and organic solvents.     

Reconstructing the knee joint mechanism from kinematic data

The interpretation of joint kinematics data in terms of displacements is a product of the type of movement, the measurement technique and the underlying model of the joint implemented in optimization procedures. Kinematic constraints reducing the number of degrees of freedom (DOFs) are expected to compensate for measurement errors and noise, thus, increasing the reproducibility of joint angles. One approach already successfully applied by several groups approximates the healthy human knee joint as a compound hinge joint with minimal varus/valgus rotation. Most of these optimizations involve an orthogonality constraint. This contribution compares the effect of a model with and without orthogonality constraint on the obtained joint rotation angles. For this purpose, knee joint motion is simulated to generate kinematic data without noise and with normally distributed noise of varying size. For small noise the unconstrained model provides more accurate results, whereas for larger noise this is the case for the constrained model. This can be attributed to the shape of the objective function of the unconstrained model near its minimum.     

Computation of Best Simultaneous Approximations with a Singularity

Simultaneous approximation errors are generally discontinuous when the function to be approximated contains a zero in its domain of definition. In this article we indicate how the presence of such a zero (or, equivalently, the resulting singularity in the error expression) affects the computational schemata for finding all the best approximations. In particular, we develop an algorithm and show that its convergence rate is “best possible expected” in the sense that it is quadratic, as in the case for continuous errors. Numerical examples are provided.     

New pyrazolyl-dibenzo[b,e][1,4]diazepinones: room temperature one-pot synthesis and biological evaluation

Molecular Diversity - Several new (5-aryloxy-pyrazolyl)- and (5-aryl/olefin-sulfanyl-pyrazolyl)-dibenzo[b,e] [1,4] diazepinone scaffolds have been synthesized, by assembling 5-substituted...     

The half-sandwich titanocene CpTiIIICl2 as efficient system for the preparation of 2,5-dihydrofurans via α-allenols

The half-sandwich titanocene reagent CpTi^IIICl₂, obtained by in situ reduction of commercial CpTiCl₃ with manganese, is an excellent system for the Barbier-type reaction between aldehydes and propargylic halides, leading to homopropargylic alcohols and α-allenols. An efficient and straightforward methodology for the conversion of aldehydes into 2,5-dihydrofurans involving a two-step sequence (Ti^III addition-Ag^I cyclization) is presented. The usefulness of the method is proved by the preparation of a Natural Product: a dihydrofuranic labdane, isolated from the leaves of Mikania sp. nov.     

Shortwave Infrared Fluorofluorophores for Multicolor In Vivo Imaging**

Developing chemical tools to detect and influence biological processes is a cornerstone of chemical biology. Here we combine two tools which rely on orthogonality– perfluorocarbons and multiplexed shortwave infrared (SWIR) fluorescence imaging– to visualize nanoemulsions in real time in living mice. Drawing inspiration from fluorous and SWIR fluorophore development, we prepared two SWIR-emissive, fluorous-soluble chromenylium polymethine dyes. These are the most red-shifted fluorous fluorophores– “fluorofluorophores”—to date. After characterizing the dyes, their utility was demonstrated by tracking perfluorocarbon nanoemulsion biodistribution in vivo. Using an excitation-multiplexed approach to image two variables simultaneously, we gained insight into the importance of size and surfactant identity on biodistribution.