Methyl Oct-cis-2-enoate. its synthesis,GLC behaviour and infrared spectra

Methyl oct-cis-2-enoate was synthesized by selective hydrogenation of methyl oct-2-ynoate at atmospheric pressure with quinoline poisoned palladium as catalyst. The resulting product contained only 7% of thetrans form, as determined by GLC. The structure was confirmed by infrared spectra. Analysis of the infrared spectra is given. The cis andtrans forms of methyl oct-2-enoate were separable by GLC in polar or non-polar columns. GLC runs in polar and non-polar phases showed that the α position of the double bond of methyl oct-2-enoate so affects its properties, that practically no interaction was observed between the double bond and the polar phase. Consequently volatility was the main factor determining the retention times of cis andtrans methyl oct-2-enoate in the polar and non-polar phases studied.     

Hepatic cysts: a case report and anatomicopathological and clinico-therapeutic considerations

The recent observation of a case of non-parasitic cyst of the liver brought the authors to a literature review. A 62 year old male, affected by type 2 diabetes and hypertension, after a CT scan and ETG, underwent resection and "capitonnage" of the cyst. Three months after surgery a CT scan showed a complete repletion of the cavity previously occupied by the cyst as a consequence of regeneration and reorganization of the hepatic parenchyma. In conclusion, hepatic cysts are rare and clinically relevant only when huge. The diagnosis is possible with the use of ETG and CT scan of the abdomen, however, in some cases angiography is also useful. The intervention of choice is the "capitonnage" of the cyst.     

Poly-bagging predictors for classification modelling for credit scoring

Credit scoring modelling comprises one of the leading formal tools for supporting the granting of credit. Its core objective consists of the generation of a score by means of which potential clients can be listed in the order of the probability of default. A critical factor is whether a credit scoring model is accurate enough in order to provide correct classification of the client as a good or bad payer. In this context the concept of bootstraping aggregating (bagging) arises. The basic idea is to generate multiple classifiers by obtaining the predicted values from the fitted models to several replicated datasets and then combining them into a single predictive classification in order to improve the classification accuracy. In this paper we propose a new bagging-type variant procedure, which we call poly-bagging, consisting of combining predictors over a succession of resamplings. The study is derived by credit scoring modelling. The proposed poly-bagging procedure was applied to some different artificial datasets and to a real granting of credit dataset up to three successions of resamplings. We observed better classification accuracy for the two-bagged and the three-bagged models for all considered setups. These results lead to a strong indication that the poly-bagging approach may promote improvement on the modelling performance measures, while keeping a flexible and straightforward bagging-type structure easy to implement.     

X-SAR interferometry: first results

Repeat-pass interferometry data were acquired during the first and second SIR-C/X-SAR missions in April and October 1994. This paper presents the first results from X-SAR interferometry at four different sites. The temporal separations were one day and six months. At two sites the coherence requirements were met, resulting in high quality interferograms. A digital elevation model in ground range geometry has been derived. The limitations of the X-SAR interferometry are discussed     

Intralesional Infiltrations of Arteriosclerotic Tissue Cells-Free Filtrate Reproduce Vascular Pathology in Healthy Recipient Rats

Lower-extremity arterial disease is a major health problem with increasing prevalence, often leading to non-traumatic amputation, disability and mortality. The molecular mechanisms underpinning abnormal vascular wall remodeling are not fully understood. We hypothesized on the existence of a vascular tissue memory that may be transmitted through soluble signaling messengers, transferred from humans to healthy recipient animals, and consequently drive the recapitulation of arterial wall thickening and other vascular pathologies. We examined the effects of the intralesional infiltration for 6 days of arteriosclerotic popliteal artery-derived homogenates (100 µg of protein) into rats’ full-thickness wounds granulation tissue. Animals infiltrated with normal saline solution or healthy brachial arterial tissue homogenate obtained from traumatic amputation served as controls. The significant thickening of arteriolar walls was the constant outcome in two independent experiments for animals receiving arteriosclerotic tissue homogenates. This material induced other vascular morphological changes including an endothelial cell phenotypic reprogramming that mirrored the donor’s vascular histopathology. The immunohistochemical expression pattern of relevant vascular markers appeared to match between the human tissue and the corresponding recipient rats. These changes occurred within days of administration, and with no cross-species limitation. The identification of these “vascular disease drivers” may pave novel research avenues for atherosclerosis pathobiology.     

Photometric method for measuring crazing in transparent plastic materials

An optical method has been developed to provide quantitative results useful for characterizing the crazing of transparent plastics. The procedure consists of the detection of discontinuities in a beam of light that scans the specimen in a direction perpendicular to the line of crazing. The light is transmitted to a photomultiplier that is connected with an amplifying system and a recorder that provides a diagram of the light energy modulated by the lines of crazing. The specimen is scanner both before and after subjecting it to a treatment that causes crazing, and the crazing index is considered to be the difference between the area below the two curves.     

Hydrophobic methacrylic copolymers containing azobenzene moieties

The functionalization of polymer materials to produce hydrophobic surfaces is an important goal for a number of applications, especially those associated with self-cleaning and anti-adherent surfaces. Azopolymers are known for photoisomerization property that can lead to photoinduced anisotropy, photomechanical effect and surface modification with surface-relief gratings. In this study, we combine the low surface energy property of perfluoroalkyl methacrylates with the photoinduced characteristics of azopolymers, by fabricating cast films of copolymers of 2,2,2 trifluorethyl methacrylate (TFEMA) or 2,2,3,3,4,4,5,5 octafluoropentyl methacrylate (OFPMA) and 4′-[N-ethyl-N-(2methacryloxy-ethyl)]amine-4-nitro-azobenzene (DR13MA). The intended structures of the copolymers synthesized using radicalar polymerization was confirmed with Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR). The polymers had much higher thermal stability than conventional azopolymers, and formed hydrophobic surfaces with a water contact angle of ca. 96°. These hydrophobic azopolymers were amenable to the formation of surface-relief gratings at room temperature resulting from an all-photonic mass transport process, which opens the way for a number of new applications to be designed.     

Prediction of contact maps with neural networks and correlated mutations

Contact maps of proteins are predicted with neural network-basedmethods, using as input codings of increasing complexity includingevolutionary information, sequence conservation, correlatedmutations and predicted secondary structures. Neural networksare trained on a data set comprising the contact maps of 173non-homologous proteins as computed from their well resolvedthree-dimensional structures. Proteins are selected from theProtein Data Bank database provided that they align with atleast 15 similar sequences in the corresponding families. Thepredictors are trained to learn the association rules betweenthe covalent structure of each protein and its contact map witha standard back propagation algorithm and tested on the sameprotein set with a cross-validation procedure. Our results indicatethat the method can assign protein contacts with an averageaccuracy of 0.21 and with an improvement over a random predictorof a factor >6, which is higher than that previously obtainedwith methods only based either on neural networks or on correlatedmutations. Furthermore, filtering the network outputs with aprocedure based on the residue coordination numbers, the accuracyof predictions increases up to 0.25 for all the proteins, withan 8-fold deviation from a random predictor. These scores arethe highest reported so far for predicting protein contact maps.     

Palladium(II) extraction from concentrated chloride media: Reactions involving thioamide derivatives

This work focuses on the detailed study of the palladium(II) extraction reactions by N-methyl-N-phenyl-octanthioamide (MPHTA) and N-methyl-N-cyclohexyl-octanthioamide (MCHTA) in toluene, since their ability to efficiently and selectively recover Pd(II) from a wide range of HCl concentrations is already known. Equilibrium data are presented and discussed, and further complemented by information depicted from UV–visible and NMR spectra. The determined apparent molar volumes show that MPHTA is monomeric, and MCHTA exhibits a slight tendency to aggregate. The Pd(II) extraction reactions by MPHTA and MCHTA are equivalent until 4.5 M HCl, passing through the formation of inner-sphere complexes with the metal ion.