Investigation of the Aquatic Photolytic and Photocatalytic Degradation of Citalopram

This study investigated the direct and indirect photochemical degradation of citalopram (CIT), a selective serotonin reuptake inhibitor (SSRI), under natural and artificial solar radiation. Experiments were conducted in a variety of different operating conditions including Milli-Q (MQ) water and natural waters (lake water and municipal WWT effluent), as well as in the presence of natural water constituents (organic matter, nitrate and bicarbonate). Results showed that indirect photolysis can be an important degradation process in the aquatic environment since citalopram photo-transformation in the natural waters was accelerated in comparison to MQ water both under natural and simulated solar irradiation. In addition, to investigate the decontamination of water from citalopram, TiO₂-mediated photocatalytic degradation was carried out and the attention was given to mineralization and toxicity evaluation together with the identification of by-products. The photocatalytic process gave rise to the formation of transformation products, and 11 of them were identified by HPLC-HRMS, whereas the complete mineralization was almost achieved after 5 h of irradiation. The assessment of toxicity of the treated solutions was performed by Microtox bioassay (Vibrio fischeri) and in silico tests showing that citalopram photo-transformation involved the formation of harmful compounds.     

In-air broad beam ionoluminescence microscopy as a tool for rocks and stone artworks characterisation

Broad beam ionoluminescence (IL) microscopy is a promising technique for the non-destructive characterisation of rocks and stone objects. Luminescence imaging by means of broad ion beams has been sporadically used by other authors but, to our knowledge, its potential has not yet been fully investigated, neither in geological science nor in other fields. The in-air broad beam IL microscope was developed and installed at the INFN-LABEC external microbeam in Florence. Similar to the cathodoluminescence (CL) microscope, the apparatus exploits a CCD colour camera collecting images (few square millimetres wide, with ~10-μm spatial resolution) of the luminescence emitted by the sample hit by a defocused megaelectron volt (MeV) proton beam. The main differences with the well-established and widespread CL are the possibility of working in air (no sampling or conductive coatings required) and the possibility of combining the analysis with microbeam analysis, such as, for example, μ-IL and μ-PIXE (particle-induced X-ray emission). To show the potential of the technique, IL images of thin sections of lapis lazuli are compared with those obtained by means of an in-vacuum cold CL. An application to the study of stone artworks is also reported. This technique and apparatus will provide a valuable help for interdisciplinary applications, e.g. in geological sciences and in the cultural heritage field.     

Prediction of properties of biodiesel-diesel blends using spectrofluorimetry and multivariate calibration

Regressions based on fluorescence spectroscopy were developed to provide relatively inexpensive and rapid measurements of the concentration, viscosity, and specific gravity of biodiesel-diesel blends. The methods involved obtaining a mathematical model from spectrofluorimetric data and data from a given property (concentration, dynamic viscosity, or specific gravity) using partial least squares (PLS) regression, which was then applied as a model for predicting properties of interest. The predicted concentrations, dynamic viscosities, and specific gravities of the biodiesel-diesel blends were compared with actual values and agreed reasonably well with the obtained results. The models showed high correlation between real and predicted values. The R-square values near 1 indicated excellent model accuracy for predicting concentrations, specific gravities, and dynamic viscosities of biodiesel-diesel blends. The residual distribution did not follow a trend with respect to the predicted variables, indicating an excellent fit to the data.      

Multilevel optimization for PDAE-constrained optimal control problems with pointwise constraints on control and state

We have developed a fully adaptive optimization environment suitable to solve complex optimal control problems restricted by partial differential algebraic equations (PDAEs) and pointwise constraints on the control [1, 2]. This contribution is devoted to the inclusion of pointwise constraints on the state within the optimization environment. To this end we first give a brief introduction into the architecture of the environment and the inclusion of pointwise constraints on the state by Moreau-Yosida regularization. Then, we test the new tool by applying it to an optimal boundary control problem for the cooling of hot glass down to room temperature, modeled by radiative heat transfer and semi-transparent boundary conditions. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Cysteine-reactive polymers synthesized by atom transfer radical polymerization for conjugation to proteins

In this communication we report a strategy for the synthesis of semitelechelic polymers reactive to cysteines. An initiator modified with a pyridyl disulfide was prepared and used for the CuBr/2,2'-bipyridine-mediated atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate. Polydispersity indices (M(w)/M(n)) of the polymers with different molecular weights were 1.25 or less. The pyridyl disulfide end group was preserved during the polymerization and allowed direct conjugation of the polymer to cysteine residues of bovine serum albumin. The described method provides a general way for the preparation of protein-polymer conjugates through a reversible disulfide bond without the need for postsynthesis modification of the polymers.     

Total synthesis of the potent antitumor polyketide (-)-callystatin A

A highly convergent and efficient total synthesis of the potent antitumor polyketide (-)-callystatin A is described. The synthesis required 19 steps from N-propionyl oxazolidinone 23 and produced the desired product in 3.5% overall yield.     

The Effects of Temperature of Condensation on the Thermal Stability and Morphology of 1,4-Phenylenediamine-1-Propylsilica Xerogels

1,4-phenylenediamine-1-propylsilica hybrid xerogels were obtained for two composition at different temperatures of gelation, from 5 up to 70C. The morphological effects produced by the different gelation temperatures were investigated by using N₂ adsorption-desorption isotherms and scanning electron microscopy. The thermal stability of the organic groups and their distribution on the xerogel matrix, i.e. the fraction of the organic groups that were trapped in closed pores, formed during the xerogel synthesis, and the fraction of organic groups present on the surface, were obtained by using infrared thermal analysis. The higher porosity of the xerogels and the higher thermal stability of the organic groups were achieved for samples gelled at 25C.     

Nanomotors

This minireview discusses whether catalytically active macromolecules and abiotic nanocolloids, that are smaller than motile bacteria, can self-propel. Kinematic reversibility at low Reynolds number demands that self-propelling colloids must break symmetry. Methods that permit the synthesis and fabrication of Janus nanocolloids are therefore briefly surveyed, as well as means that permit the analysis of the nanocolloids’ motion. Finally, recent work is reviewed which shows that nanoagents are small enough to penetrate the complex inhomogeneous polymeric network of biological fluids and gels, which exhibit diverse rheological behaviors.     

Selective Targeting of Lymphoma Cells by Monoclonal Antibody Grafted onto Zwitterionic-Functionalized Nanoparticles

Nanomedicine is considered a promising alternative to improve cancer diagnosis and treatment. Particularly, the use of nanoparticles (NPs) has enabled the encapsulation of highly toxic anticancer drugs, facilitated ultimate targeting, and allowed tailoring of drug delivery. However, when in biological fluids, these NPs are coated by proteins which hide the targeting moieties and suppress the engineered biological outcome. Herein, how the Ki-1 monoclonal antibody (mAb) can preserve its targetability through grafting on the surface of zwitterionic-functionalized nanoparticles, is unveiled. Zwitterions, known for their stealth ability, are used to minimize unspecific NPs protein adsorption and consequently maintain mAb functionality. In this work, Ki-1 mAb is used as it recognizes TNFRSF8 (CD30⁺) transmembrane protein overexpressed on CD30⁺ lymphoma cells such as L540 cells. While nonfunctionalized NPs show negligible toxic effects toward L540 cells, the Ki-1-functionalized structure demonstrates cytotoxicity, since they undergo cellular uptake, suggesting a receptor-mediated internalization. This dual-functionalization strategy provides a promising multifunctional nanoplatform toward future personalized medicine applications, minimizing unspecific protein adsorption on NPs and ensuring selective cancer cell targeting.     

Influence of pH and Salt on the Photocrosslinking in Polyelectrolyte Thymine‐Containing Films

Photocrosslinking of thymine‐based water‐soluble polymer films was investigated at varying preparation conditions. Adding salt or decreasing the pH of the solution from which the films were cast resulted in the decreased efficiency of photoimmobilization, while increasing the pH was found to increase the photoimmobilization efficiency. A mechanistic rationale for the observed effects is proposed.