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71.
Giorgia Possamai Enzo Menna Michele Maggini Maurizio Carano Massimo Marcaccio Francesco Paolucci Dirk M Guldi Angela Swartz 《Photochemical & photobiological sciences》2006,5(12):1154-1164
A cyclopropanation reaction has been used to prepare two methanofullerenes bearing a 2,2'-bipyridine () or pyridine () ligand separated from the fullerene through an oxyethylene macrocyclic spacer. Derivatives and were, in turn, employed to synthesize two fullerene-based ruthenium(ii) and rhenium(i) donor-acceptor dyads whose molecular structure was confirmed by (1)H NMR, (13)C NMR and exact mass determination. The UV-Vis spectrum of the dyads is the superimposition of those of appropriate model systems, indicating that ground-state electronic interactions between the constituent chromophores, in solution, are negligible, in line also with the electrochemical results. The complex voltammetric pattern was characterized by the superimposition of signals attributed to one moiety or another without significant shifts with respect to their models. Furthermore, both species undergo partial chemical degradation in the time scale of cyclic voltammetry upon their multiple reduction. Photophysical properties of and , namely, excited state interactions between the ruthenium(ii) or rhenium(i) complexes and [60]fullerene have been investigated by steady-state and time-resolved UV-Vis-NIR luminescence spectroscopy that was complemented by nanosecond laser flash photolysis in CH(2)Cl(2) solutions. All experimental findings were set into relation with the corresponding reference compounds. More precisely, excitation of the metal complexes in and gives rise to a notable steady-state and time-resolved luminescence quenching of both metal to ligand charge transfer states (i.e., [Ru(bpy)(3)](2+) and [(bpy)Re(CO)(3)(py)](+)). Conclusive evidence about the nature of the photoproducts came from nanosecond laser flash photolysis. In these experiments, only the long-lived and oxygen-sensitive [60]fullerene triplets were detected. Two pathways are envisioned for this [60]fullerene triplet formation. Firstly, intramolecular transduction of the triplet excited state energy evolving from the photoexcited metal complexes. Secondly, intersystem crossing of directly excited [60]fullerene. 相似文献
72.
Viral Glycoproteins Accumulate in Newly Formed Annulate Lamellae following Infection of Lymphoid Cells by Human Herpesvirus 6 总被引:1,自引:0,他引:1
Giorgia Cardinali Massimo Gentile Mara Cirone Claudia Zompetta Luigi Frati Alberto Faggioni Maria Rosaria Torrisi 《Journal of virology》1998,72(12):9738-9746
Ultrastructural analysis of HSB-2 T-lymphoid cells and human cord blood mononuclear cells infected with human herpesvirus 6 revealed the presence, in the cell cytoplasm, of annulate lamellae (AL), which were absent in uninfected cells. Time course analysis of the appearance of AL following viral infection showed that no AL were visible within the first 72 h postinfection and that their formation correlated with the expression of the late viral glycoprotein gp116. The requirement of active viral replication for AL neoformation was further confirmed by experiments using inactivated virus or performed in presence of the viral DNA polymerase inhibitor phosphonoacetic acid. Both conventional electron microscopic examination and immunogold fracture labeling with anti-endoplasmic reticulum antibodies indicated a close relationship of AL with the endoplasmic reticulum and nuclear membranes. However, when the freeze-fractured cells were immunogold labeled with an anti-gp116 monoclonal antibody, AL membranes were densely labeled, whereas nuclear membranes and endoplasmic reticulum cisternae appeared virtually unlabeled, showing that viral envelope glycoproteins selectively accumulate in AL. In addition, gold labeling with Helix pomatia lectin and wheat germ agglutinin indicated that AL cisternae, similar to cis-Golgi membranes, contain intermediate, but not terminal, forms of glycoconjugates. Taken together, these results suggest that in this cell-virus system, AL function as a viral glycoprotein storage compartment and as a putative site of O-glycosylation. 相似文献
73.
Lisa Rizzetto Daniela C. Ifrim Silvia Moretti Noemi Tocci Shih-Chin Cheng Jessica Quintin Giorgia Renga Vasilis Oikonomou Carlotta De Filippo Tobias Weil Bastiaan A. Blok Marcello S. Lenucci Manuel A. S. Santos Luigina Romani Mihai G. Netea Duccio Cavalieri 《The Journal of biological chemistry》2016,291(15):7961-7972
The immune system is essential to maintain the mutualistic homeostatic interaction between the host and its micro- and mycobiota. Living as a commensal, Saccharomyces cerevisiae could potentially shape the immune response in a significant way. We observed that S. cerevisiae cells induce trained immunity in monocytes in a strain-dependent manner through enhanced TNFα and IL-6 production upon secondary stimulation with TLR ligands, as well as bacterial and fungal commensals. Differential chitin content accounts for the differences in training properties observed among strains, driving induction of trained immunity by increasing cytokine production and direct antimicrobial activity both in vitro and in vivo. These chitin-induced protective properties are intimately associated with its internalization, identifying a critical role of phagosome acidification to facilitate microbial digestion. This study reveals how commensal and passenger microorganisms could be important in promoting health and preventing mucosal diseases by modulating host defense toward pathogens and thus influencing the host microbiota-immune system interactions. 相似文献
74.
Genetic and Functional Analysis of Polymorphisms in the Human Dopamine Receptor and Transporter Genes in Small Cell Lung Cancer
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77.
Giorgia?BeffaEmail author Tiziana?Pedrotta Daniele?Colombaroli Paul?D.?Henne Jacqueline?F.?N.?van Leeuwen Pascal?Süsstrunk Petra?Kaltenrieder Carole?Adolf Hendrik?Vogel Salvatore?Pasta Flavio?S.?Anselmetti Erika?Gobet Willy?Tinner 《Vegetation History and Archaeobotany》2016,25(3):271-289
Little is known about the vegetation and fire history of Sardinia, and especially the long-term history of the thermo-Mediterranean belt that encompasses its entire coastal lowlands. A new sedimentary record from a coastal lake based on pollen, spores, macrofossils and microscopic charcoal analysis is used to reconstruct the vegetation and fire history in north-eastern Sardinia. During the mid-Holocene (c. 8,100–5,300 cal bp), the vegetation around Stagno di Sa Curcurica was characterised by dense Erica scoparia and E. arborea stands, which were favoured by high fire activity. Fire incidence declined and evergreen broadleaved forests of Quercus ilex expanded at the beginning of the late Holocene. We relate the observed vegetation and fire dynamics to climatic change, specifically moister and cooler summers and drier and milder winters after 5,300 cal bp. Agricultural activities occurred since the Neolithic and intensified after c. 7,000 cal bp. Around 2,750 cal bp, a further decline of fire incidence and Erica communities occurred, while Quercus ilex expanded and open-land communities became more abundant. This vegetation shift coincided with the historically documented beginning of Phoenician period, which was followed by Punic and Roman civilizations in Sardinia. The vegetational change at around 2,750 cal bp was possibly advantaged by a further shift to moister and cooler summers and drier and milder winters. Triggers for climate changes at 5,300 and 2,750 cal bp may have been gradual, orbitally-induced changes in summer and winter insolation, as well as centennial-scale atmospheric reorganizations. Open evergreen broadleaved forests persisted until the twentieth century, when they were partly substituted by widespread artificial pine plantations. Our results imply that highly flammable Erica vegetation, as reconstructed for the mid-Holocene, could re-emerge as a dominant vegetation type due to increasing drought and fire, as anticipated under global change conditions. 相似文献
78.
Solano AF Leipnitz G De Bortoli GM Seminotti B Amaral AU Fernandes CG Latini AS Dutra-Filho CS Wajner M 《Free radical research》2008,42(8):707-715
The present work investigated the in vitro effects of isovaleric acid (IVA) and isovalerylglycine (IVG), which accumulate in isovaleric acidemia (IVAcidemia), on important parameters of oxidative stress in supernatants and mitochondrial preparations from brain of 30-day-old rats. IVG, but not IVA, significantly increased TBA-RS and chemiluminescence values in cortical supernatants. Furthermore, the addition of free radical scavengers fully prevented IVG-induced increase of TBA-RS. IVG also decreased GSH concentrations, whereas IVA did not modify this parameter in brain supernatants. Furthermore, IVG did not alter lipid peroxidation or GSH concentrations in mitochondrial preparations, indicating that the generation of oxidants by IVG was dependent on cytosolic mechanisms. On the other hand, IVA significantly induced carbonyl formation both in supernatants and purified mitochondrial preparations from rat brain, with no effect observed for IVG. Therefore, it is presumed that oxidative damage may be at least in part involved in the pathophysiology of the neuropathology of IVAcidemia. 相似文献
79.
80.
Radi M Crespan E Botta G Falchi F Maga G Manetti F Corradi V Mancini M Santucci MA Schenone S Botta M 《Bioorganic & medicinal chemistry letters》2008,18(3):1207-1211
A series of substituted benzoylamino-2-[(4-benzyl)thio]-1,3,4-thiadiazoles has been discovered as potent Abl tyrosine kinase inhibitors. Molecular docking simulations on the Abl tyrosine kinase were conducted in order to rationalize the SAR of the synthesized inhibitors. The most active compound identified from the enzymatic screening (6a) showed interesting inhibitory activity on Imatinib-sensitive murine myeloid 3B clone and Bcr-Abl-independent Imatinib-resistant leukemia cells. Surprisingly, 6a was also proved to act as differentiating inducers in human promyelocytic leukemia cells (HL-60). 相似文献