1,260 research outputs found
Polyglycerol Sebacate Elastomer: A Critical Overview of Synthetic Methods and Characterisation Techniques
No full textPoly (glycerol sebacate) is a widely studied elastomeric copolymer obtained from the polycondensation of two bioresorbable monomers, glycerol and sebacic acid. Due to its biocompatibility and the possibility to tailor its biodegradability rate and mechanical properties, PGS has gained lots of interest in the last two decades, especially in the soft tissue engineering field. Different synthetic approaches have been proposed, ranging from classic thermal polyesterification and curing to microwave-assisted organic synthesis, UV crosslinking and enzymatic catalysis. Each technique, characterized by its advantages and disadvantages, can be tailored by controlling the crosslinking density, which depends on specific synthetic parameters. In this work, classic and alternative synthetic methods, as well as characterisation and tailoring techniques, are critically reviewed with the aim to provide a valuable tool for the reproducible and customized production of PGS for tissue engineering applications
Chromosomal unbalancements in sperm and oocytes of two Italian cattle breeds as determined by dual color fluorescent in situ hybridization (FISH)
No full textAneuploidy is one of the most important causes of embryonic and foetal mortality in mammals. In order to assess the possible risk of chromosomal abnormalities in germ cells of domestic animals we investigated the aneuploidy rates on partially decondensed sperm and in vitro matured oocytes in two cattle breeds, Italian Friesian (I.F.) and Italian Brown (I.B.), by using FISH with chromosome-specific painting probes (chromosomes X-Y for sperm and chromosomes X-5 for oocytes). For each bull, more than 5,000 sperm were analyzed, for a total of 52,586 and 51,342 sperm cells for the two breeds, respectively. Aneuploid and diploid sperm had, respectively, a frequency of 0.110% and 0.050% in the I.F. and 0.078% and 0.062% in the I.B. breeds. Out of 100 in vitro matured oocytes for each breed, on the average, diploidy affected 11.2% and 18.4% in the I.F. and I.B., respectively, whereas disomy for chromosome X-had a frequency of 2% in the I.F. and 2.5% in the I.B. breeds. Further studies are needed to expand our knowledge on frequency of aneuploidy in sperm and oocytes of domestic animals, in order to assess their impact on productive and reproductive efficiency, also in relation to climatic changes and environmental hazards
Recent developments on genetic information among river type buffaloes by chromosome microdissection and cloning
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Genome organization and X-Y chromosome aneuploidy in river buffalo (Bubalus bubalis L.) spermatozoa by multicolor fluorescence in situ hybridization (FISH) and chromosome microdissection.
No full textCorrection to: When terminology hinders research: the colloquialisms of transitions of control in automated driving (Cognition, Technology & Work, (2022), 10.1007/s10111-022-00705-3)
No full textIn the original article, author affiliation published with error. The correct affiliations are: Davide Maggi—Institute for Transport Studies, Leeds, UK. Richard Romano—Institute for Transport Studies, Leeds, UK. Oliver Carsten—Institute for Transport Studies, Leeds, UK. Joost C. F. De Winter—Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands. The original article has been corrected.Human-Robot Interactio
Glycovaccine Design: Optimization of Model and Antitubercular Carrier Glycosylation via Disuccinimidyl Homobifunctional Linker
No full textConjugation via disuccinimidyl homobifunctional linkers is reported in the literature as a convenient approach for the synthesis of glycoconjugate vaccines. However, the high tendency for hydrolysis of disuccinimidyl linkers hampers their extensive purification, which unavoidably results in side-reactions and non-pure glycoconjugates. In this paper, conjugation of 3-aminopropyl saccharides via disuccinimidyl glutarate (DSG) was exploited for the synthesis of glycoconjugates. A model protein, ribonuclease A (RNase A), was first considered to set up the conjugation strategy with mono- to tri- mannose saccharides. Through a detailed characterization of synthetized glycoconjugates, purification protocols and conjugation conditions have been revised and optimized with a dual aim: ensure high sugar-loading and avoid the presence of side reaction products. An alternative purification approach based on hydrophilic interaction liquid chromatography (HILIC) allowed the formation of glutaric acid conjugates to be avoided, and a design of experiment (DoE) approach led to optimal glycan loading. Once its suitability was proven, the developed conjugation strategy was applied to the chemical glycosylation of two recombinant antigens, native Ag85B and its variant Ag85B-dm, that are candidate carriers for the development of a novel antitubercular vaccine. Pure glycoconjugates (≥99.5%) were obtained. Altogether, the results suggest that, with an adequate protocol, conjugation via disuccinimidyl linkers can be a valuable approach to produce high sugar-loaded and well-defined glycovaccines
Admiel Kosman, Siamo giunti a Dio
No full textInternational audienceSix poems from Israeli poet Admiel Kosman translated from the Hebrew into Italian. Selection of poems, presentation of the author, translation and notes by Davide Mano
Estimation of the baseline level of aneuploidy in germ and reproductive health in domestic animals
No full textThe reproductive health of a given species is strictly
related to the karyological integrity of the breeding
animals (i.e., absence of chromosomal abnormalities)
and to the precision with which the haploid chromosomes
are segregated into the male (sperm) and
female (oocyte) germ cells prior to fertilization. This
assumption is supported by the fact that in mammals
more than 70% of the embryonic mortality is
attributed to aneuploidies in the germ cells which
give rise to genetically unbalanced embryos (monosomic
or trisomic) destined to abortion, thus reducing
fertility and the reproductive/productive efficiency of
the animal production industry.
Estimation of the ‘baseline’ level of aneuploidy in
sperm and in in vitro matured oocytes with the
corresponding first polar body in domestic animal
species and breeds/genetic types is now possible by
using the fluorescent in situ hybridization (FISH)
technique and chromosome specific painting probes
obtained via microdissection and DOP-PCR. Such a
‘baseline’ level could be used as ‘control reference’
not only for improving the in vitro production of
embryos destined to the animal production industry
but also, and more importantly, for monitoring future
trends of the reproductive health of the domestic
species/breeds engaged in zootechnical productions,
especially in relation to the increasing risk of environmental challenges and hazards, such as chemical
contaminants in the water, soil, air, micotoxins in
the feedstuff, hormone unbalancements, nutritional
and dietetical mistakes, and other factors which are
known to damage the mitotic and meiotic machinery
of the cells
Cytogenetic characterization of the yak (Bos Grunniens) and comparison with cattle (Bos taurus)
No full textThe domestic yak (Bos grunniens) belongs to the family Bovidae and is one of the most important species for the economy of the Asian high lands. Recently, the interest for this species increased also in European countries, mainly because of its meat and milk characteristics. Furthermore, it is a species well adapted to marginal conditions and it could be used to preserve mountain territories economy. We carried out a detailed investigation on this species with the following main aims: 1) to perform a cytogenetic screening of a yak herd recently introduced in Italy; 36 out of 60 animals were analyzed by conventional and GTG-banding karyotype. All animals were 2n=and no chromosomal abnormalities were found, confirming that the introduced herd is a good nucleus to start up with yak farming in Italy; 2) to determine the genetic stability of the animals reared under Italian conditions; two different tests were used: “Chromatid/chromosome breaks” and “Sister chromatid exchange (SCE)”. Out of 400 analyzed cells, 3.75% showed one or more anomalies; the most represented were chromosome and chromatid breaks. The mean number of SCE/cells was 5.2%. Comparison with cattle revealed that the two species have the same percentage of chromosome anomalies, while SCE frequency is lower in yak compared to cattle; 3) to increase the cytogenetic knowledge about this species and compare Bos taurus and Bos grunniens in relation to male sterility of F1 hybrids; C-, R-, and G-banded karyotypes of yak were prepared and compared with the standard karyotypes of cattle. To identify Nucleolar Organizer Regions, sequential NOR’s/R banded karyotypes were performed. Despite the two species share a very high degree of banding homology, some differences can be pointed out; the most remarkable is on the centromeric region of chromosome 15, where a strong positive band is present in Bos grunniens while absent in Bos taurus. Molecular data indicate that in yak, unlike in cattle, the X chromosome has retained a homologous sequence (182 bp) to the Y chromosome. To verify if larger blocks of chromatin are involved, FISH analysis of yak metaphases using X and Y cattle painting probe was performed. The lack of unspecific signal indicated that no large blocks of chromatin are interested. Finally, we mapped two genes (SRY: sex-determining region Y gene and ZFY: zinc finger protein, Y-linked) on the yak Y chromosome to verify if this chromosome, like in other species, such as Bos indicus, underwent rearrangement during evolution. The two genes mapped at the same position compared to cattle, indicating that the sterility of F1 hybrids seems not to be due to Y chromosomal rearrangements relatively to the these two genes
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