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IL DIFETTO OSSIDATIVO E LE ALTERAZIONI DEL DNA MITOCONDRIALE IN TOPI TRANSGENICI MODELLO ANIMALE DELLA ATASSIA SPINOCEREBELLARE DI TIPO 1
No full textSpinocerebellar ataxias (SCAs) are a genetically heterogeneous group of cerebellar degenerative disorders, characterized by progressive gait unsteadiness, hand incoordination and dysarthria. The mutational mechanism in spinocerebellar ataxia type1 (SCA1), a dominantly inherited form of SCA, consists of an expanded trinucleotide CAG repeat that encodes a polyglutamine tract in ataxin1.
Mutant SCA1 transgenic mice present pathological cerebellar signs with concomitant progressive Purkinje neuron atrophy and relatively little cell loss, at least in the early stage of life; this evidence suggests that the SCA1 phenotype is not the result of cell death per se, but a possible effect of cellular dysfunction that occurs before neuronal demise.
In the present study we correlated the earliest histopathological changes in both homozygous and heterozygous transgenic SCA1 mice, 2 and 6 months old, to the mitochondrial oxidative metabolism in cerebellar cells.
Our results showed selective Cytochrome c Oxidase (COX) deficiency in Purkinje cells (PC). Analysis on COX-competent and -deficient PC, isolated by laser-microdissector, demonstrated that the observed oxidative dysfunction is related to mitochondrial DNA (mtDNA) depletion.
In conclusion, we provide evidence of a selective oxidative metabolism defect in neuronal PC expressing mutant ataxin. This defect could represent one of the earliest pathogenetic step of the Purkinje cells’ suffering in SCA1 disease
A case of non-electroselective and .pi.-facial non-stereoselective addition to norbornadiene
No full textAdditions of Azomethine Ylides to Fullerene C60 Assisted by a Removable Anchor
No full textThe addition of nitrile oxides to [60]fullerene, leading to isoxazolinofullerenes, can be reversed
using reducing agents such as Mo(CO)6 or DIBALH. Thus, this reaction can be used, in principle,
for protection/deprotection of [60]fullerene or for solubilization purposes. The tether-controlled
tandem addition of nitrile oxides and azomethine ylides provides mainly cis-1 patterns. The
determination of the structure of bisadducts was obtained by NMR spectroscopy with the help of
HMQC, HMBC, and NOEDS techniques. The isoxazoline moiety could be removed using Mo(CO)6
leaving a fulleropyrrolidine derivativ
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Selective Reduction of Cyclic Conjugate Enones With Nabh4 In the Presence of Cyclodextrins
No full text3,4 AND 4',5'-PHOTOCYCLOADDUCTS BETWEEN 4'-METHYLANGELICIN AND THYMINE FROM DNA
No full textTwo C4-cycloadducts between 4′-methylangelicin and thymine were isolated from the photo-reaction (365 nm) between this furocoumarin and DNA. Their capacity to undergo photoreversion at 254 nm and their spectroscopic and NMR data allowed us to assign furan- and pyrone-side structures, respectively, to these photocompounds. The former adduct has a cis-syn configuration; the latter. which was also isolated from a photoreaction between the furocoumarin and thymine in water-methanol solution, was assigned a cis-anti structure
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