NMR and statistical study of olive oils from Lazio: A geographical,ecological and agronomic characterization

NMR and statistical procedures were used to analyse olive oils obtained from trees grown in different areas of Lazio, an Italian region, under different irrigation conditions. In order to obtain information on “real” commercial olive oils and to study the effects of some agronomical and ecological factors on the olive oil composition, we studied commercial multi-varietal olive oils, all produced in well-characterized areas of Lazio. ¹H and ¹³C NMR techniques, coupled to a suitable multivariate statistical procedure, were used to analyse 72 multi-varietal extra virgin and PDO (Protected Denomination of Origin) olive oils harvested in 2003, from the northern area, the centre and the southern area of Lazio. The intensity of selected ¹H and ¹³C NMR variables were submitted to three different statistical methods, namely, analysis of variance (ANOVA), principal component analysis (PCA) and linear discriminant analysis (LDA). ¹H and ¹³C NMR spectroscopy allowed us to obtain a good chemical characterization of the samples, giving information on major and minor compounds with an experimental error exactly the same and always extremely low for all the analyzed components. As a result of the statistical analysis, olive oils from the same geographical areas were well grouped. Since the amounts of some minor volatile components, such as aldehydes, terpenes and squalene, as well as, the content of β-sitosterol, the most important sterol present in olive oils, are sensitive to the pedoclimatic conditions, the intensity of the corresponding NMR signals turned out to be the most discriminating factors in the geographic classification. Moreover, the NMR and statistical protocol allowed us to investigate the roles of irrigation and altitude on the olive oil composition: the contents of oleic and saturated fatty acids turned out to be strongly influenced by the irrigation practice, whereas the content of volatile compounds was sensitive to the altitude of the olive trees. As a result of our study, olive oils were well grouped according to the irrigation practice as well as to the altitude at which olive trees were grown.     

Transfusion-associated or nosocomial hepatitis G virus infection in patients undergoing surgery

BACKGROUND: Despite blood donor screening, there are still cases of transfusion-associated hepatitis. From 1988 to 1992, a prospective study was conducted on the incidence of non-A, non-B posttransfusion hepatitis (PTH). STUDY DESIGN: The present investigation was designed to determine if transfusion recipients with PTH who are negative for hepatitis C virus (HCV) were positive for hepatitis G virus (HGV). Patients admitted for surgery who had normal liver tests and no transfusions during the previous 6 months were enrolled. Alanine amino transferase levels were determined monthly for 6 months after surgery and for 1 year in the case of PTH (defined as alanine aminotranferase twice the upper limit of normal in two consecutive assays). HGV RNA and E2 antibodies were tested for in samples from transfusion recipients with or without PTH and from nontransfused patients. RESULTS: Of the 308 blood recipients who were enrolled in the study, 21 (6.8%) had PTH. HGV RNA was detected at the onset of hepatitis in 3 patients with PTH (14%), 2 of whom were also anti-HCV and HCV RNA positive. One patient developed E2 antibodies without detectable HGV RNA. Three (10.7%) of 28 recipients of an allogeneic transfusion without PTH developed HGV infection. HGV RNA was also found in two nontransfused patients, which suggests nosocomial transmission of HGV. CONCLUSION: Some cases of PTH are associated with HGV; most cases of postoperative HGV infection are not associated with liver abnormalities; and most PTH cases are not associated with known hepatotropic viruses.     

Outils spécialisés de synthèse VLSI pour algorithmes de traitement numérique du signal

Special-purpose silicon compilers are instrumental in making possible efficient implementations of complex digital signal processing systems on a single chip. This paper presents three such tools, each of them adapted to a specific kind of algorithm and throughput range, that generate the layout of avlsi block, based on a fixed target architecture, directly from its high-level specification. Fidys and Genrif respectively generate recursiveldi andfir vlsi digital filters, starting from behavioral frequency template specifications. The architecture is a direct one to one mapping from the filter structure. Fidys targets low-end and medium-range applications, using bit-serial architecture, whereas the bit-parallel architecture in Genrif is better adapted to high-end video applications. Cots is a more general-purpose tool that implements any C program on a customized microcoded datapath.     

Synthesis and biological evaluation of phosphate prodrugs of 4-phospho-D-erythronohydroxamic acid, an inhibitor of 6-phosphogluconate dehydrogenase

We have previously reported the discovery of potent and selective inhibitors of 6-phosphogluconate dehydrogenase, the third enzyme of the phosphate pentose pathway, from Trypanosoma brucei, the causative organism of human African trypanosomiasis. These inhibitors were charged phosphate derivatives with restricted capacity to enter cells. Herein, we report the synthesis of five different classes of prodrugs: phosphoramidate; bis-S-acyl thioethyl esters (bis-SATE); bis-pivaloxymethyl (bis-POM); CycloSaligenyl; and phenyl, S-acyl thioethyl mixed phosphate esters (mix-SATE). Prodrugs were studied for stability and activity against the intact parasites. Most prodrugs caused inhibition of the growth of the parasites. The activity of the prodrugs against the parasites appeared to be related to their stability in aqueous buffer.     

A fast single-chip implementation of 8192 complex point FFT

Large-scale single-frequency networks are now being considered in Europe as very promising network topologies to achieve drastic savings in spectrum usage for digital terrestrial television transmission. Such networks are possible using the COFDM system, with large guard intervals (more than 200 μs) to absorb long echoes. In order to limit the spectral efficiency loss to about 20%, very long size fast Fourier transforms (up to 8 K complex points) have to be performed in real time for the demodulation of every COFDM symbol (every 1 ms). This paper presents the first VLSI single chip dedicated to the computation of direct or inverse fast Fourier transforms of up to 8192 complex points. Due to its pipelined architecture, it can perform an 8 K FFT every 400 μs and a 1 K FFT every 50 μs. All the storage is onchip, so that no external memories are required. A new internal result scaling technique, called convergent block floating point, has been introduced in order to minimize the required storage for a given quantization noise, The chip, 1 cm² large with 1.5 million transistors, has been designed in a 3.3 V-0.5 μm triple-level metal CMOS process and is fully functional. The 8 K complex FFT function could therefore be introduced in the coming years in digital terrestrial TV receivers at low cost