Experience in implementing a Document Delivery Service

In this paper we propose an integration between electronic mail and web services for people such as library operators who need to send large files to Internet users. The proposed solution permits librarians to continue using the e-mail service to send large documents, but at the same time overcomes problems that users can encounter downloading large size files with e-mail agents. The library operator sends the document as an attachment to the destination address, on fly the e-mail server extracts and saves the attachments in a web-server disk file and substitutes then with a new message part that includes the URL pointing to the saved document. The receiver can download these large objects using user-friendly browser

Cytosolic 5'-Nucleotidase II Is a Sensor of Energy Charge and Oxidative Stress: A Possible Function as Metabolic Regulator

Cytosolic 5'-nucleotidase II (NT5C2) is a highly regulated enzyme involved in the maintenance of intracellular purine and the pyrimidine compound pool. It dephosphorylates mainly IMP and GMP but is also active on AMP. This enzyme is highly expressed in tumors, and its activity correlates with a high rate of proliferation. In this paper, we show that the recombinant purified NT5C2, in the presence of a physiological concentration of the inhibitor inorganic phosphate, is very sensitive to changes in the adenylate energy charge, especially from 0.4 to 0.9. The enzyme appears to be very sensitive to pro-oxidant conditions; in this regard, the possible involvement of a disulphide bridge (C175-C547) was investigated by using a C547A mutant NT5C2. Two cultured cell models were used to further assess the sensitivity of the enzyme to oxidative stress conditions. NT5C2, differently from other enzyme activities, was inactivated and not rescued by dithiothreitol in a astrocytoma cell line (ADF) incubated with hydrogen peroxide. The incubation of a human lung carcinoma cell line (A549) with 2-deoxyglucose lowered the cell energy charge and impaired the interaction of NT5C2 with the ice protease-activating factor (IPAF), a protein involved in innate immunity and inflammation

Bibliometric S & T Indicators to Comply with Users' Needs.

Homogeneous and easy to update scientometric indicators for a wide spectrum of problems were obtained making use of the bibliographic database Current Contents. The procedures adopted and the major factors which can affect the accuracy of the results are reported and discussed. Case studies are presented concerning: (i) international co-operation, (ii) foreign policy and (iii) vocation for industrial settlements, which provide examples of how these indicators can comply with a variety of needs

OWL-Cat: A Web-Based OPAC Appealing End-Users to Exploit Library Resources

The structure and functionalities of OWL-Cat (Online Web Library-Catalogue Access), a tool designed to interface DBMS Basis Plus and its Library Management Module Techlib Plus ver. L1G.2 to the World Wide Web are described

Un servizio di ricerca su archivi istituzionali di e-prints al CNR di Bologna

Presentazione di un sistema di interfaccia unica per l'interrogazione simultanea di più archivi locali e remoti, realizzato dall'Area di ricerca del CNR di Bologna

Molecular mechanisms of nucleoside recycling in the brain

A major role of plasma membrane bound ectonucleotidases is the modulation of ATP, ADP, adenosine (the purinergic agonists), UTP, and UDP (the pyrimidinergic agonists) availability in the extracellular space at their respective receptors. We have recently shown that an ATP driven uridine-UTP cycle is operative in the brain, based on the strictly compartmentalized processes of uridine salvage to UTP and uridine generation from UTP, in which uptaken uridine is anabolized to UTP in the cytosol, and converted back to uridine in the extracellular space by the action of ectonucleotidases (Ipata et al. Int J Biochem Cell Biol 2010;42:932-7). In this paper we show that a similar cytidine-CTP cycle exists in rat brain. Since (i) brain relies on imported preformed nucleosides for the synthesis of nucleotides, RNA, nuclear and mitochondrial DNA, coenzymes, pyrimidine sugar- and lipid-conjugates and (ii) no specific pyrimidinergic receptors have been identified for cytidine and their nucleotides, our results, taken together with previous studies on the intra- and extracellular metabolic network of ATP, GTP, UTP, and their nucleosides in the brain (Barsotti and Ipata. Int J Biochem Cell Biol 2004;36:2214-25; Balestri et al. Neurochem Int 2007;50:517-23), strongly suggest that, apart from the modulation of ligand availability, ectonucleotidases may serve the process of local nucleoside recycling in the brain

Metabolic interplay between intra- and extra-cellular uridine metabolism via an ATP driven uridine-UTP cycle in brain

Uridine, a pyrimidine nucleoside essential for the synthesis of RNA and biomembranes, has several trophic functions in the central nervous system, that involve a physiological regulation of pyrimidine nucleotides and phospholipids content, and a maintenance of brain metabolism under ischemia, or pathological situations. The understanding of uridine production in the brain is therefore of fundamental importance. Brain has a limited capacity to synthesize ex novo the pyrimidine ring, and a reasonable source of brain uridine is UTP. The kinetics of UTP breakdown, as catalysed by post-mitochondrial brain extracts and membrane preparations reported herein suggests that in normoxic conditions uridine is locally generated in brain exclusively in the extracellular space, and that any uptaken uridine is salvaged to UTP. It is now well established that cytosolic UTP can be released to interact with a subset of P2Y receptors, inducing a variety of molecular and cellular effects, leading to neuroprotection, while uridine is uptaken via an equilibrative or a Na(+)-dependent transport system, to exert its trophic effects in the cytosol. An ATP driven uridine-UTP cycle can be envisaged, based on the strictly compartmentalized processes of uridine salvage to UTP and uridine generation from UTP, in which uptaken uridine is anabolised to UTP in the cytosol, and converted back to uridine in extracellular space