Comparison between NIR, MIR, concatenated NIR and MIR analysis and hierarchical PLS model. Application to virgin olive oil analysis.

This work investigates the potential use of simultaneously near-infrared (NIR) and mid-infrared (MIR) spectroscopies for the quantitative analysis of fatty acids and triacylglycerols and for identifying the Registered Designation of Origin (RDO) of extra virgin olive oils. The two spectral ranges were used separately using PLS and PLS-DA regressions. To combine both information, concatenated matrix was used at the first time, multiblock method using H-PLS models were constructed at the second time. The models were compared in terms of prediction errors. The results obtained with MIR spectroscopy are better than the ones obtained with NIR spectroscopy. The H-PLS methodology seems to be very interesting for quantitative analysis with the use of additional information in the NIR range, which is not present in the MIR one. For RDO identification by discriminant analysis, the use of multiblock method was less efficient.

Infrared study of aging of edible oils by oxidative spectroscopic index and MCR-ALS chemometric method.

One of the most suitable analytical techniques used for edible oil quality control is Fourier transform mid infrared spectroscopy (FT-MIR). FT-MIR spectroscopy was used to continuously characterize the aging of various edible oils thanks to a specific aging cell. There were differences in the spectra of fresh and aged oils from different vegetable sources, which provide the basis of a method to classify them according to the oxidative spectroscopic index value. The use of chemometric treatment such as multivariate curve resolution-alternative least square (MCR-ALS) made it possible to extract the spectra of main formed and degraded species. The concentration profiles gave interesting information about the ability of the various oils to support the oxidative treatment and showed that all oils present the same aging process. Both methods led to concordant results in terms of induction times determined by the oxidative spectroscopic index and the appearance of oxidation products revealed by MCR-ALS.

Lipid compositions and French registered designations of origins of virgin olive oils predicted by chemometric analysis of mid-infrared spectra.

The combination of mid-infrared (MIR) spectroscopy with multivariate analysis provides an original approach to study the profile of virgin olive oils (VOOs) in relation to composition and geographical origin. Chemometric treatment of mid-infrared spectra (n=402) is assessed for quantification of fatty acids (14 components) and triacylglycerols (19 components) in VOO samples and for classification into six very geographically closed registered designations of origin (RDOs) of French VOO ("Aix-en-Provence", "Haute-Provence", "Vallée des Baux de Provence", "Nice", "Nîmes", and "Nyons"). Spectroscopic interpretation of regression vectors has shown that each RDO is correlated to one specific component of VOO according to their cultivar compositions. The results are satisfactory, in spite of the similarity of cultivar compositions between two denominations of origin ("Aix-en-Provence" and "Vallée des Baux de Provence"). Chemometric treatment of MIR spectra makes it possible to obtain similar results to those obtained by time-consuming analytical techniques such as gas chromatography (GC) and high-performance liquid chromatography (HPLC) and constitutes a fast and robust tool for authentication of these French VOOs.

Geographic origins and compositions of virgin olive oils determinated by chemometric analysis of NIR spectra.

The authentication of virgin olive oil samples requires usually the use of sophisticated and time consuming analytical techniques. There is a need for fast and simple analytical techniques for the objective of a quality control methodology. Virgin olive oils present characteristic NIR spectra. Chemometric treatment of NIR spectra was assessed for the quantification of fatty acids and triacylglycerols in virgin olive oil samples (n=125) and for their classification (PLS1-DA) into five very geographically closed registered designations of origin (RDOs) of French virgin olive oils ("Aix-en-Provence", "Haute-Provence", "Nice", "Nyons" and "Vallée des Baux"). The spectroscopic interpretation of regression vectors showed that each RDO was correlated to one or two specific components of virgin olive oils according to their cultivar compositions. The results were quite satisfactory, in spite of the similarity of cultivar compositions between two denominations of origin ("Aix-en-Provence" and "Vallée des Baux"). Chemometric treatments of NIR spectra allow us to obtain similar results than those obtained by time consuming analytical techniques such as GC and HPLC, and constitute a help fast and robust for authentication of those French virgin olive oils.

Knee arthroscopy after yttrium or osmic acid injection.

This study presents the macroscopic and histologic results of 35 knee arthroscopies performed on patients with rheumatoid arthritis, some months after an yttrium or osmic acid intraarticular injection. The procedure was most often performed after a failure of the injection or a relapse of synovitis. Arthroscopy provides an understanding of the cause of synoviorthesis failure--insufficient action of the product on the synovitis or its poor diffusion, fibri-nonecrotic deposits, or cartilaginous lesions--and may be used both diagnostically and therapeutically.

[Auditory reaction time, a maturation index in the athletic child?]. / Le temps de réaction auditif, un index maturatif chez l'enfant sportif?

Auditive reaction time (A.R.T.) measured with a chronoscope, is a simple way of estimating sensorimotor qualities. It is one of the tests we use to evaluate the physical aptitude of sportsmen. It has been shown that A.R.T. decreases with chronological age up to the end of puberty. In the present study, regular check ups were realized in control children and in different groups of children practising sports. A.R.T. was plotted against the chronological age to obtain curves similar to the height curves and weight curves used in pediatrics. We confirmed the above mentioned relation. A.R.T. curves were not linear but decreasing asymptotic. Some groups of children (gymnasts, ice-skaters) presented a delay in skeletal maturation as compared with the chronological age. This delay was sometimes considerable. Therefore, we sought for a correlation between A.R.T. and bone age. A better correlation than that obtained between A.R.T. and chronological age would allow a more accurate evaluation of the physical aptitudes of such children, since a delayed maturation can lead to an erroneous estimation of their sports qualities. If correlated, A.R.T. could become an index to be used in the evaluation of the maturation and of the somatic development in children. Our results show that A.R.T., a reflection of central nervous system maturation, was in fact more related to chronological age - i.e. to lifespan and psychomotor experience - than to bone age - i.e. to biological and endocrine maturation. This shows, once more, that maturation is not a homogeneous process.

[Cleidocranial dysostosis. Contribution to its study apropos of 2 personal cases (an isolated and a familial form)]. / La dysostose cléido-crânienne. Contribution à son étude à propos de deux cas personnels (une forme isolée et une forme familiale).

Cleidocranial dysostosis is a rare embryopathy affecting the whole osseous system. Anomalies predominate on skull, chest and dentition but the whole skeleton can be affected especially pelvic girdle and spine. An autosomal transmission is often demonstrable; isolated forms are very uncommon. We present two cases fortuitously diagnosed in our ward: a familial cleidocraniopelvic major form and an incomplete isolated form. The treatment must be especially oriented towards dental malformations.