Mapping CAP-A satellite DNAs by FISH in Sapajus cay paraguay and S. macrocephalus (Platyrrhini, Primates)

Satellite DNAs such as Cap-A sequences are potentially informative taxonomic and phylogenetic markers useful for characterizing primate genomes. They have also been used as cytogenetic markers facilitating species identification in many taxa. The aim of this work is to map Cap-A sequences by FISH (fluorescent in situ hybridization) on two Platyrrhini (Primates) species genomes, Sapajus cay paraguay and S. macrocephalus, in order to study their distribution pattern on chromosomes. The CapA probes showed bright signals with almost the same interstitial pattern of distribution in correspondence with C and CMA3 rich regions on six pairs of chromosomes in both Sapajus species. An additional pair was detected on S. macrocephalus. The analysis of the results, compared with previous literature data on other phylogenetically close New World species, shows that Cap-A satellite sequences have a genus-specific pattern, but with slight species-specific patterns that are useful as phylogenetic and taxonomic markers

Recent Approaches for Chemical Speciation and Analysis by Electrospray Ionization (ESI) Mass Spectrometry

In recent years, the chemical speciation of several species has been increasingly monitored and investigated, employing electrospray ionization mass spectrometry (ESI-MS). This soft ionization technique gently desolvates weak metal\u2013ligand complexes, taking them in the high vacuum sectors of mass spectrometric instrumentation. It is, thus, possible to collect information on their structure, energetics, and fragmentation pathways. For this reason, this technique is frequently chosen in a synergistic approach to investigate competitive ligand exchange-adsorption otherwise analyzed by cathodic stripping voltammetry (CLE-ACSV). ESI-MS analyses require a careful experimental design as measurement may face instrumental artifacts such as ESI adduct formation, fragmentation, and sometimes reduction reactions. Furthermore, ESI source differences of ionization efficiencies among the detected species can be misleading. In this mini-review are collected and critically reported the most recent approaches adopted to mitigate or eliminate these limitations and to show the potential of this analytical technique

Centromeric enrichment of LINE-1 retrotransposon in two species of South American monkeys Alouatta belzebul and Ateles nancymaae (Platyrrhini, Primates)

LINE-1 sequences have been linked to genome evolution, plasticity and speciation; however, despite their importance, their chromosomal distribution is poorly known in primates. In this perspective, we used fluorescence in situ hybridiza-tion (FISH) to map LINE-1 probes onto two representative platyrrhine species, Aotus nancymaae (Cebidae) and Alouatta belzebul (Atelidae), both characterized with highly rearranged karyotypes, in order to investigate their chromosomal distribution and role and to better characterize the two genomes. We found centromeric enrichment of LINE-1 sequences on all biarmed and acrocentric chromosomes co-localized with heterochromatin C-positive bands. This distribution led us to hypothesize that LINE 1 sequences may have a role in the centromere architecture and karyotype organization of platyrrhine genome

Characterization of gas phase aggregates of bis(2-ethylhexyl)sulfosuccinate (AOT) and divalent metal ions. Elimination of radical species in the decomposition pathways of even-electron [AOTMIICl2]– anions

Structure and properties of even-electron anionic species formed by bis(2-ethylhexyl)sulfosuccinate (AOT) and divalentmetal ions (MII) with stoichiometry [AOTMIICl2]– have been investigated by using electrospray ionization and different mass spectrometry techniques, such as high resolution, accurate mass measurements, collision-induced dissociation (CID) multiple-stage mass spectrometry.Owing to CID, eliminations of neutrals,mainly consisting in hydrochloric acid, 2-ethyl-1-hexene and 2-ethylhexanol, and an unexpected loss of an alkyl radical have been observed. The radical anions [C4HO6SMIICl]–• so produced have been characterized by MS3 experiments. Density functional theory calculations have been carried out for investigating structure and stability of the ionic species formed in the decomposition pathways

Degrees of freedom effect on fragmentation in tandem mass spectrometry of singly charged supramolecular aggregates of sodium sulfonates

The characteristic collision energy (CCE) to obtain 50% fragmentation of positively and negatively single charged non-covalent clusters has been measured. CCE was found to increase linearly with the degrees of freedom (DoF) of the precursor ion, analogously to that observed for synthetic polymers. This suggests that fragmentation behavior (e.g. energy randomization) in covalent molecules and clusters are similar. Analysis of the slope of CCE with molecular size (DoF) indicates that activation energy of fragmentation of these clusters (loss of a monomer unit) is similar to that of the lowest energy fragmentation of protonated leucine-enkephalin. Positively and negatively charged aggregates behave similarly, but the slope of the CCE vs DoF plot is steeper for positive ions, suggesting that these are more stable than their negative counterparts

Elucidation of peptide metabolism by on-line immunoaffinity liquid chromatography mass spectrometry

An immunoaffinity chromatography extraction capillary liquid chromatography separation has been coupled to electrospray ionization mass spectrometry for on-line characterization of drug metabolites of a therapeutic peptide in plasma. It is demonstrated that the selectivity, sensitivity and molecular weight data provided by immunoaffinity chromatography coupled to liquid chromatography/mass spectrometry provides a means of rapidly achieving qualitative determinations of small amounts of material in complicated biological matrices such as plasma. The ability to detect the peptide in rat plasma at a level of 10 14ng/mL is demonstrated using this method. In addition, experiments to study the epitope of the peptide by enzymatic digestion and mass spectrometry are also discussed. The method is proposed as an alternative approach to studying the metabolism of therapeutic peptides. Copyright © 2000 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35079/1/868_ftp.pd

Photo-oxidative and soil burial degradation of irrigation tubes based on biodegradable polymer blends

Irrigation tubes based on biodegradable polymers were prepared via an extrusion-drawing process by Irritec and compared to conventional pipes made of high-density polyethylene (HDPE). A commercial polylactide/poly (butyleneadipate-co-butyleneterephthalate) (PLA/PBAT) blend (Bio-Flex®) and Mater-Bi® were used. The polymers were characterized from rheological and mechanical points of view. Irrigation pipes were subjected to photoaging with continued exposure to UV radiation up to 22 days. The degradability in the soil of irrigation tube samples was studied. The influence of temperature and UV irradiation on soil burial degradation was investigated. A soil burial degradation test was carried out at 30 °C and 50 °C for up to 70 days. The degree of degradation was evaluated from the weight loss percentage. The degradation rate of irrigation tube samples based on Mater-Bi® was higher at 30 °C and was stimulated after 14 days of UV irradiation. Higher temperatures or UV aging encouraged the disintegration in soil of Bio-Flex®-based irrigation tubes. Furthermore, tube samples, before and after UV and soil burial degradation, were analyzed by Attenuated Total Reflection-Fourier Transform Infra-Red (ATR-FTIR) spectroscop

Poly-L-Lactic Acid (PLLA)-Based Biomaterials for Regenerative Medicine: A Review on Processing and Applications

Synthetic biopolymers are effective cues to replace damaged tissue in the tissue engineering(TE) field, both for in vitro and in vivo application. Among them, poly-L-lactic acid (PLLA) has beenhighlighted as a biomaterial with tunable mechanical properties and biodegradability that allowsfor the fabrication of porous scaffolds with different micro/nanostructures via various approaches.In this review, we discuss the structure of PLLA, its main properties, and the most recent advancesin overcoming its hydrophobic, synthetic nature, which limits biological signaling and proteinabsorption. With this aim, PLLA-based scaffolds can be exposed to surface modification or combinedwith other biomaterials, such as natural or synthetic polymers and bioceramics. Further, variousfabrication technologies, such as phase separation, electrospinning, and 3D printing, of PLLA-basedscaffolds are scrutinized along with the in vitro and in vivo applications employed in various tissuerepair strategies. Overall, this review focuses on the properties and applications of PLLA in theTE field, finally affording an insight into future directions and challenges to address an effectiveimprovement of scaffold properties

Morphology, rheological and mechanical properties of isotropic and anisotropic PP/rPET/GnP nanocomposite samples

The effect of graphene nanoplatelets (GnPs) on the morphology, rheological, and mechanical properties of isotropic and anisotropic polypropylene (PP)/recycled polyethylene terephthalate (rPET)-based nanocomposite are reported. All the samples were prepared by melt mixing. PP/rPET and PP/rPET/GnP isotropic sheets were prepared by compression molding, whereas the anisotropic fibers were spun using a drawing module of a capillary viscometer. The results obtained showed that the viscosity of the blend is reduced by the presence of GnP due to the lubricating effect of the graphene platelets. However, the Cox–Merz rule is not respected. Compared to the PP/rPET blend, the GnP led to a slight increase in the elastic modulus. However, it causes a slight decrease in elongation at break. Morphological analysis revealed a poor adhesion between the PP and PET phases. Moreover, GnPs distribute around the droplets of the PET phase with a honey-like appearance. Finally, the effect of the orientation on both systems gives rise not only to fibers with higher modulus values, but also with high deformability and a fibrillar morphology of the dispersed PET phase. A fragile-ductile transition driven by the orientation was observed in both systems

Temporal trends of heavy metals in sediment core from the gulf of Palermo (Sicily, Italy)

The evaluation of long–term heavy metal concentrations in the Gulf of Palermo was carried out in this study. Measurements of Cr, Cu, Hg, Pb and Zn concentrations were performed by atomic absorption spectrophotometry (AAS) on dated fractions of a sediment core, dated by the 210Pbex method. They are found to cover a time period from 1951 to 2004. The constant sedimentation rate model was used for dating. Specific activities of 137Cs have also been measured in the sediment core sections as a check of the time scale derived by the 210Pbex method. A time-series analysis based on temporal decomposition was used in order to investigate the presence of heavy metal pollution trend. The additive component model, widely used to estimate seasonal and long–term behavior, was chosen for the temporal analysis. Results showed the presence of a specific heavy metal concentration trend. Residual time–autocorrelation has also been taken into account in order to investigate their stochastic properties. Concentrations of some metals (Cu, Hg, and Zn) have been found increasing until the beginning of the 1970s. A peak around the beginning of the 1980s has been found for Cr and Pb. Heavy metal concentration in the sediment core show a significant decreasing after these years. Our results for the concentration time trends are in good agreement with other surveys performed in different areas of the world, and they can be explained in terms of the reduction of anthropogenic contribution to atmospheric emissions. Further investigations on time properties and spatial distributions, are also planned