[Optical spectroscopy: a new approach to assess urological tumors]. / La spectroscopie optique : une nouvelle approche pour l'étude des tumeurs urologiques.

INTRODUCTION: Optical spectroscopy refers to a group of novel technologies that uses interaction of light with tissues to analyze their structure and chemical composition. The objective of this article is to describe these technologies and detail their potential for assessing urological tumors. MATERIAL AND METHODS: It has been shown that optical spectroscopy can accurately analyse multiple solid tumors. Several publications specifically aimed at assessing prostate cancers, renal carcinomas and urothelial tumors. RESULTS: There are three types of spectroscopy that all use light focussed on a tissue and thereafter collect a specific reflected optical signal. Optical spectroscopy can differentiate benign (adenoma or inflammation) and malignant (adenocarcinoma) prostatic tissues. It can also distinguish normal bladder tissue from inflammatory or cancerous cells. Regarding renal tumors, spectroscopy can identify normal and tumoral tissue and differentiate benign and malignant tumors. Its diagnostic accuracy is about 85%. However, reported studies only concentrate on in vitro or ex vivo specimen and the numbers of patients are quite small. CONCLUSION: Optical spectroscopy can be envisioned as an "optical biopsy" tool. Potential applications in the clinical field are promising. Larger studies on in vivo specimen need to be undertaken to confirm phase I preliminary reports.

Synthesis of alcoholic ZnO nanocolloids in the presence of piperidine organic base: nucleation-growth evidence of Zn5(OH)8Ac2.2H2O fine particles and ZnO nanocrystals.

Piperidine as a new free OH* organic base has been successfully used to prepare Zn5(OH)8(Ac).22H2O particles (named Zn-HDS) or concentrated alcoholic ZnO sols. Considering the applications of Zn-HDS and ZnO compounds, as well as interests of these synthesis mechanisms for fundamental chemistry, such investigations are of importance. This strategy not only allows preparing Zn-HDS compounds at room temperature but also brings evidence of some new nucleation-growth, and permits the preparation of well crystalline ZnO nanocrystals at low temperature (maximum 60 degrees C). It was possible to convincingly prove that the formation of Zn-HDS phase is concomitant to the ZnO nanocrystals formation and that Zn-HDS could be considered as an intermediate initiator of ZnO nanocrystals. A parallel approach was used for the fast screening of the synthesis progress.

Discovery of Novel Catalysts for Allylic Alkylation with a Visual Colorimetric Assay.

The first non-phosphane iridium catalyst, made from [{IrCl(cod)}(2)] and iPr-pybox (shown schematically; cod=1,5-cyclooctadiene), for allylic alkylation in neutral medium was discovered by a simple, rapid, and inexpensive screening assay. The red coloration upon treatment of the reaction mixtures with Fast Red (see the 96-well plate) indicates the presence of 1-naphthol and thus the occurrence of allylic alkylation.

Characterization and catechole oxidase activity of a family of copper complexes coordinated by tripodal pyrazole-based ligands.

A family of tripodal pyrazole-based ligands has been synthesized by a condensation reaction between 1-hydroxypyrazoles and aminoalcohols. The diversity was introduced both on the substituents of the pyrazole ring and on the side chain. The corresponding copper(II) complexes have been prepared by reaction with CuCl(2) in tetrahydrofuran. They have been characterized by EPR, UV spectroscopy and cyclic voltammetry. The absence of the half-field splitting signals in EPR suggests that the complex exists in solution as mononuclear species. The influence of substituents and side chain of the tripodal ligand on the catecholase activity of the complexes was studied. The reaction rate depends on two factors. First, the presence of an oxygen atom in the third position of the side chain should be avoided to keep the effectiveness of the reaction. Second, the electronic and steric effects of substituents on the pyrazole ring strongly affect the catalytic activity of the complex. Thus, best results were obtained with complexes containing unsubstituted pyrazole based-ligands. Kinetic investigations with the best catalyst based on the Michaelis-Menten model show that the catalytic activity of the mononuclear complex is close to that of some dicopper complexes described in literature.