Integration of capillary and EWOD technologies for autonomous and low-power consumption micro-analytical systems

This work presents a miniaturized system combining, on the same microfluidic chip, capillarity and electrowetting-on-dielectric (EWOD) techniques for movement and control of fluids. The change in hydrophobicity occurring at the edge between a capillary channel and a hydrophobic layer is successfully exploited as a stop-and-go valve, whose operation is electronically controlled through the EWOD electrodes. Taking into account the variety of microfluidic operation resulting from the combination of the two handling techniques and their characteristic features, this work prompts the development of autonomous, compact and low-power consumption lab-on-chip systems

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Plasmid replication initiator RepB forms a hexamer reminiscent of ring helicases and has mobile nuclease domains

47 p.-7 fig. Boer, Roeland et alt.RepB initiates plasmid rolling-circle replication by binding to a triple 11-bp direct repeat (bind locus) and cleaving the DNA at a specific distant site located in a hairpin loop within the nic locus of the origin. The structure of native full-length RepB reveals a hexameric ring molecule, where each protomer has two domains. The origin-binding and catalytic domains show a three-layer α–β–α sandwich fold. The active site is positioned at one of the faces of the β-sheet and coordinates a Mn2+ ion at short distance from the essential nucleophilic Y99. The oligomerization domains (ODs), each consisting of four α-helices, together define a compact ring with a central channel, a feature found in ring helicases. The toroidal arrangement of RepB suggests that, similar to ring helicases, it encircles one of the DNA strands during replication to confer processivity to the replisome complex. The catalytic domains appear to be highly mobile with respect to ODs. This mobility may account for the adaptation of the protein to two distinct DNA recognition sitesThis study was supported by the Spanish Ministerio de Ciencia e Innovación (Grants BFU2005-06758/BMC and BFU2008-02372 to MC, BIO2006-02668 to FXGR, BFU2007-63575 to GdS, SAF2005-00775/SAF2008-00451 to OL, BFU2007-65977 to PC and CSD00013 to ME), the Generalitat de Catalunya (Grant 2005SGR-00280 to MC), the Fundació La Marató de TV3 (Grant 052810 to MC), the Comunidad de Madrid (Grants S-BIO-0214-2006 to OL and PC and CM-BIO0260-2006 to ME), the Red Temática de Investigación Cooperativa en Cáncer (Grant RD06/0020/1001 to OL), the Human Frontiers Science Program (Grant RGP39/2008 to OL and PC) and the EU (Spine2-Complexes LSHG-2006-031220 and 3D-Repertoire LSHG-CT-2005-512028 projects). Synchrotron data collection was supported by the ESRF and the EUPeer reviewe

Visualization of DNA-induced conformational changes in the DNA repair kinase DNA-PKcs

The catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs) is essential for the repair of double-stranded DNA breaks (DSBs) in non- homologous end joining (NHEJ) and during V(D)J recombination. DNA-PKcs binds single- and double-stranded DNA in vitro, and in vivo the Ku heterodimer probably helps recruit it to DSBs with high affinity. Once loaded onto DNA, DNA-PKcs acts as a scaffold for other repair factors to generate a multiprotein complex that brings the two DNA ends together. Human DNA-PKcs has been analysed by electron microscopy in the absence and presence of double-stranded DNA, and the three-dimensional reconstruction of DNA-bound DNA-PKcs displays large conformational changes when compared with the unbound protein. DNA-PKcs seems to use a palm-like domain to clip onto the DNA, and this new conformation correlates with the activation of the kinase. We suggest that the observed domain movements might help the binding and maintenance of DNA-PKcs’ interaction with DNA at the sites of damage, and that these conformational changes activate the kinase

Architecture of the pontin/reptin complex, essential in the assembly of several macromolecular complexes

10 pages, 6 figures.-- PMID: 18940606 [PubMed].-- PMCID: PMC2577609 [Available on 2009/10/01].-- Supplementary information (Suppl. figures S1-S5, 5 pages) available at: http://www.structure.org/cgi/content/full/16/10/1511/DC1/The cryo-EM map of yeast pontin/reptin complex has been deposited in the 3D EM database (http://www.ebi.ac.uk/msd/) under accession code EMD-2865.Pontin and reptin belong to the AAA+ family, and they are essential for the structural integrity and catalytic activity of several chromatin remodeling complexes. They are also indispensable for the assembly of several ribonucleoprotein complexes, including telomerase. Here, we propose a structural model of the yeast pontin/reptin complex based on a cryo-electron microscopy reconstruction at 13 Å. Pontin/reptin hetero-dodecamers were purified from in vivo assembled complexes forming a double ring. Two rings interact through flexible domains projecting from each hexamer, constituting an atypical asymmetric form of oligomerization. These flexible domains and the AAA+ cores reveal significant conformational changes when compared with the crystal structure of human pontin that generate enlarged channels. This structure of endogenously assembled pontin/reptin complexes is different than previously described structures, suggesting that pontin and reptin could acquire distinct structural states to regulate their broad functions as molecular motors and scaffolds for nucleic acids and proteins.This work was supported by projects SAF2005-00775 and SAF2008-00451 (O.L.), BFU2006-02907 (S.A.), and BFU2007-65977/BMC (P.C.) from the Spanish Ministry of Science, CAM S-BIO-0214-2006 (O.L. and P.C.) from the Autonomous Region of Madrid and CA89406 from the National Institutes of Health (A.D.). Llorca’s group was additionally supported by project RD06/0020/1001 of the Red Temática Investigación Cooperativa en Cáncer (RTICC) and the Human Frontiers Science Program Organization (RGP39/2008). E.A.P. was supported by a contract from the Autonomous Region of Madrid. We are also grateful for the support of the computing resources from the Galicia Supercomputer Centre (CESGA) and the Barcelona Supercomputing Centre, Spain.Peer reviewe

Integration of Capillary and EWOD Technologies for Autonomous and Low-power Consumption Micro-analytical Systems

This work presents a miniaturized system combining, on the same microfluidic chip, capillarity and electrowetting-on-dielectric (EWOD) techniques for movement and control of fluids. The change in hydrophobicity occurring at the edge between a capillary channel and a hydrophobic layer is successfully exploited as a stop-and-go valve, whose operation is electronically controlled through the EWOD electrodes. Taking into account the variety of microfluidic operation resulting from the combination of the two handling techniques and their characteristic features, this work prompts the development of autonomous, compact and low-power consumption lab-on-chip systems

IBERIFIER Reports – Legal and Political Aspects of Disinformation in Portugal and Spain

In Portugal and Spain, disinformation is a severe concern for social and cultural reasons. Furthermore, it is a significant concern for politicians and policymakers (Wardle & Derakhshan, 2017; Lanoszka, 2019; Saurwein & Spencer-Smith, 2020; Tenove, 2020; Correyero-Ruiz & Baladrón-Pazos, 2022). According to McKay & Tenove (2021), disinformation can undermine trust in democratic institutions and influence election outcomes, harming the reputation of individuals or institutions (European Commission, 2021; Department of National Security of the Spanish Government, 2022). In Portugal, the Government established a task force to combat disinformation, promoted media literacy, and launched campaigns to raise awareness of the dangers of disinformation. Similarly, in Spain, the Government established a Strategic Communication Office to coordinate efforts to combat disinformation and launched campaigns to promote media literacy

IBERIFIER Reports – Legal and Political Aspects of Disinformation in Portugal and Spain

In Portugal and Spain, disinformation is a severe concern for social and cultural reasons. Furthermore, it is a significant concern for politicians and policymakers (Wardle & Derakhshan, 2017; Lanoszka, 2019; Saurwein & Spencer-Smith, 2020; Tenove, 2020; Correyero-Ruiz & Baladrón-Pazos, 2022). According to McKay & Tenove (2021), disinformation can undermine trust in democratic institutions and influence election outcomes, harming the reputation of individuals or institutions (European Commission, 2021; Department of National Security of the Spanish Government, 2022). In Portugal, the Government established a task force to combat disinformation, promoted media literacy, and launched campaigns to raise awareness of the dangers of disinformation. Similarly, in Spain, the Government established a Strategic Communication Office to coordinate efforts to combat disinformation and launched campaigns to promote media literacy