86 research outputs found

    On the possibility of magneto-structural correlations: detailed studies of di-nickel carboxylate complexes

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    A series of water-bridged dinickel complexes of the general formula [Ni<sub>2</sub>(μ<sub>2</sub>-OH<sub>2</sub>)(μ2- O<sub>2</sub>C<sup>t</sup>Bu)<sub>2</sub>(O<sub>2</sub>C<sup>t</sup>Bu)2(L)(L0)] (L = HO<sub>2</sub>C<sup>t</sup>Bu, L0 = HO<sub>2</sub>C<sup>t</sup>Bu (1), pyridine (2), 3-methylpyridine (4); L = L0 = pyridine (3), 3-methylpyridine (5)) has been synthesized and structurally characterized by X-ray crystallography. The magnetic properties have been probed by magnetometry and EPR spectroscopy, and detailed measurements show that the axial zero-field splitting, D, of the nickel(ii) ions is on the same order as the isotropic exchange interaction, J, between the nickel sites. The isotropic exchange interaction can be related to the angle between the nickel centers and the bridging water molecule, while the magnitude of D can be related to the coordination sphere at the nickel sites

    ISG15 Modulates Development of the Erythroid Lineage

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    Activation of erythropoietin receptor allows erythroblasts to generate erythrocytes. In a search for genes that are up-regulated during this differentiation process, we have identified ISG15 as being induced during late erythroid differentiation. ISG15 belongs to the ubiquitin-like protein family and is covalently linked to target proteins by the enzymes of the ISGylation machinery. Using both in vivo and in vitro differentiating erythroblasts, we show that expression of ISG15 as well as the ISGylation process related enzymes Ube1L, UbcM8 and Herc6 are induced during erythroid differentiation. Loss of ISG15 in mice results in decreased number of BFU-E/CFU-E in bone marrow, concomitant with an increased number of these cells in the spleen of these animals. ISG15-/- bone marrow and spleen-derived erythroblasts show a less differentiated phenotype both in vivo and in vitro, and over-expression of ISG15 in erythroblasts is found to facilitate erythroid differentiation. Furthermore, we have shown that important players of erythroid development, such as STAT5, Globin, PLC γ and ERK2 are ISGylated in erythroid cells. This establishes a new role for ISG15, besides its well-characterized anti-viral functions, during erythroid differentiation

    Sox6 Is Necessary for Efficient Erythropoiesis in Adult Mice under Physiological and Anemia-Induced Stress Conditions

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    BACKGROUND: Definitive erythropoiesis is a vital process throughout life. Both its basal activity under physiological conditions and its increased activity under anemia-induced stress conditions are highly stimulated by the hormone erythropoietin. The transcription factor Sox6 was previously shown to enhance fetal erythropoiesis together and beyond erythropoietin signaling, but its importance in adulthood and mechanisms of action remain unknown. We used here Sox6 conditional null mice and molecular assays to address these questions. METHODOLOGY/PRINCIPAL FINDINGS: Sox6fl/flErGFPCre adult mice, which lacked Sox6 in erythroid cells, exhibited compensated anemia, erythroid cell developmental defects, and anisocytotic, short-lived red cells under physiological conditions, proving that Sox6 promotes basal erythropoiesis. Tamoxifen treatment of Sox6fl/flCaggCreER mice induced widespread inactivation of Sox6 in a timely controlled manner and resulted in erythroblast defects before reticulocytosis, demonstrating that impaired erythropoiesis is a primary cause rather than consequence of anemia in the absence of Sox6. Twenty five percent of Sox6fl/flErGFPCre mice died 4 or 5 days after induction of acute anemia with phenylhydrazine. The others recovered slowly. They promptly increased their erythropoietin level and amplified their erythroid progenitor pool, but then exhibited severe erythroblast and reticulocyte defects. Sox6 is thus essential in the maturation phase of stress erythropoiesis that follows the erythropoietin-dependent amplification phase. Sox6 inactivation resulted in upregulation of embryonic globin genes, but embryonic globin chains remained scarce and apparently inconsequential. Sox6 inactivation also resulted in downregulation of erythroid terminal markers, including the Bcl2l1 gene for the anti-apoptotic factor Bcl-xL, and in vitro assays indicated that Sox6 directly upregulates Bcl2l1 downstream of and beyond erythropoietin signaling. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that Sox6 is necessary for efficient erythropoiesis in adult mice under both basal and stress conditions. It is primarily involved in enhancing the survival rate and maturation process of erythroid cells and acts at least in part by upregulating Bcl2l1

    Energy Efficiency in Datacenters: the Esselunga Case Study from the IEE-PrimeEnergyIT Research Project

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    The IEE PrimeEnergyIT research project was proposed in 2009 to further enhance market development for en-ergy efficient central IT equipment based on the previous initiatives and with a focus on so far largely uncovered IT hardware, including storage and network equipment as well as new power management technologies. The best practice examples collected and presented in the research project are focused on cooling and airflow optimiza-tion, combination of free cooling and other energy efficiency measures. In this paper will be presented the two success histories of the refurbishment of an existing datacenter and the development and the operation of a new datacenter constructed in 2011-2012 by Esselunga, a large supermarket chain in Italy. The headquarter and IT infrastructure are located in the suburban area of Milano, northern Italy

    Is magnetic resonance imaging of hepatic hemangioma any different in liver fibrosis and cirrhosis compared to normal liver?

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    PURPOSE: To compare qualitative and quantitative magnetic resonance (MR) imaging characteristics of hepatic hemangiomas in patients with normal, fibrotic and cirrhotic livers. MATERIALS AND METHODS: Retrospective, institutional review board approved study (waiver of informed consent). Eighty-nine consecutive patients with 231 hepatic hemangiomas who underwent liver MR imaging for lesion characterization were included. Lesions were classified into three groups according to the patients' liver condition: no underlying liver disease (group 1), fibrosis (group 2) and cirrhosis (group 3). Qualitative and quantitative characteristics (number, size, signal intensities on T1-, T2-, and DW MR images, T2 shine-through effect, enhancement patterns (classical, rapidly filling, delayed filling), and ADC values) were compared. RESULTS: There were 160 (69%), 45 (20%), and 26 (11%) hemangiomas in groups 1, 2 and 3, respectively. Lesions were larger in patients with normal liver (group 1 vs. groups 2 and 3; P=.009). No difference was found between the groups on T2-weighted images (fat-suppressed fast spin-echo (P=.82) and single-shot (P=.25)) and in enhancement patterns (P=.56). Mean ADC values of hemangiomas were similar between groups 1, 2 and 3 (2.11±.52×10(-3)mm(2)/s, 2.1±.53×10(-3)mm(2)/s and 2.14±.44×10(-3)mm(2)/s, P=87, respectively). T2 shine-through effect was less frequently observed in cirrhosis (P=.02). CONCLUSION: MR imaging characteristics of hepatic hemangioma were similar in patients with normal compared to fibrotic and cirrhotic livers. Smaller lesion size was observed with liver disease and less T2 shine-through effect was seen in hemangiomas developed on cirrhosis, the latter being an important finding to highlight in these patients at risk of developing hepatocellular carcinoma

    Un caso di endoftalmite purulenta infettiva da Nocardia in un gatto

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    Introduzione: Al genere Nocardia appartengono elementi filamentosi che producono un micelio aereo (ife vegetative) con tendenza alla frammentazione in cellule coccoidi o bastoncellari. Questi microrganismi vivono comunemente nel suolo come saprofiti su materiali organici in decomposizione e sono responsabili di alcune forme di malattia ad andamento cronico e a carattere pio-granulomatoso. Le sedi più frequenti sono quelle cutanee, polmonari e peritoneali. Solo occasionalmente sono colpiti: sistema nervoso centrale, ossa, articolazioni e occhio. Caso clinico: Un gatto Europeo, maschio, di 5 anni, FIV-FeLV negativo, era stato condotto in visita per la presenza di una neoformazione intraoculare, inizialmente di colore rosso e poi bianco-giallastra, a carico dell’occhio sinistro. Alla visita oftalmica, oltre alla massa in camera anteriore, si evidenziavano sinechie posteriori, cataratta e ipertono oculare. Il fondo oculare non era valutabile. Tra le diagnosi differenziali venivano incluse uveite anteriore o neoplasia intraoculare. Era stato successivamente eseguito un esame ecografico oculare dal quale era emersa anche una possibile rottura della lente. La terapia topica e sistemica effettuata non risultava efficace e, per tale ragione, l’occhio veniva enucleato. Conclusioni: L’esame istologico evidenziava una grave endoftalmite purulenta da Nocardia spp., non confermando la rottura della lente ipotizzata. Considerando lo stile di vita del gatto e la presenza nell’ambiente di piante grasse con aculei, l’ipotesi eziopatogenetica più plausibile era stata quella di un trauma perforante che poteva aver veicolato l’agente patogeno in sede intraoculare, anche se non erano presenti evidenti segni di lesione corneale d’ingresso. A conoscenza degli autori in bibliografia non sono presenti analoghe segnalazioni
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