Evidence of spontaneous spin polarized transport in magnetic nanowires

The exploitation of the spin in charge-based systems is opening revolutionary opportunities for device architecture. Surprisingly, room temperature electrical transport through magnetic nanowires is still an unresolved issue. Here, we show that ferromagnetic (Co) suspended atom chains spontaneously display an electron transport of half a conductance quantum, as expected for a fully polarized conduction channel. Similar behavior has been observed for Pd (a quasi-magnetic 4d metal) and Pt (a non-magnetic 5d metal). These results suggest that the nanowire low dimensionality reinforces or induces magnetic behavior, lifting off spin degeneracy even at room temperature and zero external magnetic field.Comment: 4 pages, 3 eps fig

A consistent scalar-tensor cosmology for inflation, dark energy and the Hubble parameter

The authors are grateful for financial support to the Cruickshank Trust (CW), EPSRC/GG-Top (CW, JR), Omani Government (MA), Science Without Borders programme, CNPq, Brazil (DR), and STFC/CfFP (CW, AM, RB, JM). CW and AM acknowledge the hospitality of CERN, where this work was started. The University of Aberdeen and University of Edinburgh are charitable bodies registered in Scotland, with respective registration numbers SC013683 and SC005336.Peer reviewedPostprin

Characterization of a new Staphylococcus aureus Kayvirus harboring a lysin active against biofilms

Staphylococcus aureus is one of the most relevant opportunistic pathogens involved in many biofilm-associated diseases, and is a major cause of nosocomial infections, mainly due to the increasing prevalence of multidrug-resistant strains. Consequently, alternative methods to eradicate the pathogen are urgent. It has been previously shown that polyvalent staphylococcal kayviruses and their derived endolysins are excellent candidates for therapy. Here we present the characterization of a new bacteriophage: vB_SauM-LM12 (LM12). LM12 has a broad host range (>90%; 56 strains tested), and is active against several MRSA strains. The genome of LM12 is composed of a dsDNA molecule with 143,625 bp, with average GC content of 30.25% and codes for 227 Coding Sequences (CDSs). Bioinformatics analysis did not identify any gene encoding virulence factors, toxins, or antibiotic resistance determinants. Antibiofilm assays have shown that this phage significantly reduced the number of viable cells (less than one order of magnitude). Moreover, the encoded endolysin also showed activity against biofilms, with a consistent biomass reduction during prolonged periods of treatment (of about one order of magnitude). Interestingly, the endolysin was shown to be much more active against stationary-phase cells and suspended biofilm cells than against intact and scraped biofilms, suggesting that cellular aggregates protected by the biofilm matrix reduced protein activity. Both phage LM12 and its endolysin seem to have a strong antimicrobial effect and broad host range against S. aureus, suggesting their potential to treat S. aureus biofilm infections.This study was supported by Lisando GmbH and by the Portuguese Foundation for Science and Technology (FCT), under the scope of the scope of the project the Project PTDC/BBB-BSS/6471/2014 (POCI-01-0145-FEDER-016678), the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684), and BioTecNorte operation (NORTE-01-0145-FEDER-000004), funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte. Ana Brandão and Ergun Akturk acknowledge FCT for grants SFRH/BD/133193/2017 and PD/BD/13524/2017, respectively. The authors declare that they have no competing financial interests.info:eu-repo/semantics/publishedVersio

Origin of anomalously long interatomic distances in suspended gold chains

The discovery of long bonds in gold atom chains has represented a challenge for physical interpretation. In fact, interatomic distances frequently attain 3.0-3.6 A values and, distances as large as 5.0 A may be seldom observed. Here, we studied gold chains by transmission electron microscopy and performed theoretical calculations using cluster ab initio density functional formalism. We show that the insertion of two carbon atoms is required to account for the longest bonds, while distances above 3 A may be due to a mixture of clean and one C atom contaminated bonds.Comment: 4 pages, 4 Postscript figures, to be published in Physical Review Letter

Big data warehouse framework for smart revenue management

Revenue Management’s most cited definitions is probably “to sell the right accommodation to the right customer, at the right time and the right price, with optimal satisfaction for customers and hoteliers”. Smart Revenue Management (SRM) is a project, which aims the development of smart automatic techniques for an efficient optimization of occupancy and rates of hotel accommodations, commonly referred to, as revenue management. One of the objectives of this project is to demonstrate that the collection of Big Data, followed by an appropriate assembly of functionalities, will make possible to generate a Data Warehouse necessary to produce high quality business intelligence and analytics. This will be achieved through the collection of data extracted from a variety of sources, including from the web. This paper proposes a three stage framework to develop the Big Data Warehouse for the SRM. Namely, the compilation of all available information, in the present case, it was focus only the extraction of information from the web by a web crawler – raw data. The storing of that raw data in a primary NoSQL database, and from that data the conception of a set of functionalities, rules, principles and semantics to select, combine and store in a secondary relational database the meaningful information for the Revenue Management (Big Data Warehouse). The last stage will be the principal focus of the paper. In this context, clues will also be giving how to compile information for Business Intelligence. All these functionalities contribute to a holistic framework that, in the future, will make it possible to anticipate customers and competitor’s behavior, fundamental elements to fulfill the Revenue Managemen

Baixos níveis de glicemia e outras complicações durante suplementação de hormônio do crescimento na sepse

O perfil glicêmico esperado em pacientes pós-operatórios sépticos recebendo nutrição enteral de elevado teor calórico é de valores sanguíneos no limite superior do normal ou mesmo hiperglicemia moderada.A adição de hormônio do crescimento (GH) como agente anabólico deveria reforçar ainda mais esta tendência.Num paciente com câncer submetido a gastrectomia parcial e linfadenectomia, que se complicou no pós operatório com abscesso subfrênico e sepse prolongada, administrou-se conjuntamente dieta de sonda (38,3 kcal/kg/dia) e GH (0,17 UI/kg/dia).Antes da introdução de GH as taxas glicêmicas situavam-se nos limites inferiores do normal, e esta tendência persistiu durante a maior parte do período terapêutico.Duas complicações adicionais, nominalmente parada cardíaca e edema periférico, foram documentadas nesta mesma etapa.Conclui-se que a sepse é o mais provável mecanismo de redução da glicemia neste caso, e que o emprego de dieta enteral e de GH não conseguiu prevenir tal efeito.É questionável se a parada cardíaca foi devida ao suplemento hormonal, mas o edema periférico é um secundarismo bem conhecido deste agente em estudos clínicos.Blood glucose levels in the high normal range or even moderate hyperglycemia is the expected profile in septic postoperative patients receiving high-calorie enteral alimentation. The addition of growth hormone as an anabolic agent should additionally reinforce this tendency. In a cancer patient undergoing partial gastrectomy with lymphadenectomy and suffering from postoperative subphrenic abscess and prolonged sepsis, tube feeding (38.3 kcal/kg/day) and growth hormone (0.17 IU/kg/day) were simultaneously administered for 25 days. Blood glucose levels were in the lower limits of the normal range before growth hormone introduction, and continued with a similar tendency during most of the therapeutic period. Two additional complications, namely heart arrest and peripheral edema, were documented during the same period. It is concluded that sepsis was the most likely mechanism for low glucose values, and that high-calorie enteral diet and growth hormone supplementation did not prevent that result. It is uncertain whether heart arrest was due to the drug, but its association with peripheral edema is well documented in clinical series

Staphylococcus epidermidis biofilms are resistant to phage infection due to the protective effect of the biofilm matrix

EMBO Conference on Viruses of Microbes III: Structure and Function - from Molecules to Communities (Programme and Abstract Book)info:eu-repo/semantics/publishedVersio

Quantification of Urinary Mevalonic Acid as a Biomarker of HMG-CoA Reductase Activity by a Novel Translational LC-MS/MS Method

Background: Mevalonic acid (MVA), as a product of 3-hydroxy-3-methylglutaryl coenzyme A reductase, represents a potential multipurpose biomarker in health and disease. A translational urinary MVA quantification method was developed, validated and used to demonstrate the diurnal variation of urinary MVA excretion in rats and healthy children. Methods: Urinary MVA was converted to mevalonolactone at pH 2, extracted with ethyl acetate and quantified by reversed-phase liquid chromatography-tandem mass spectrometry. Results: The assay had a dynamic range of 0.0156-10 µg/ml with precision <15% CV, accuracy 85-115% and was transferred between laboratories. Urinary MVA excretion in rats and healthy children displayed a diurnal variation consistent with the known diurnal variation of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase activity. Conclusion: Urinary MVA can be quantified accurately over a wide dynamic range by a validated translational and transferable method with biomarker capability

Gold nanoparticles functionalised with fast water exchanging Gd3+ chelates: linker effects on the relaxivity.

This is the accepted manuscript. The final version is available at http://dx.doi.org/10.1039/C4DT03210AThe relaxivity displayed by Gd(3+) chelates immobilized onto gold nanoparticles is the result of the complex interplay between the nanoparticle size, the water exchange rate and the chelate structure. In this work we study the effect of the length of ω-thioalkyl linkers, anchoring fast water exchanging Gd(3+) chelates onto gold nanoparticles, on the relaxivity of the immobilized chelates. Gold nanoparticles functionalized with Gd(3+) chelates of mercaptoundecanoyl and lipoyl amide conjugates of the DO3A-N-(α-amino)propionate chelator were prepared and studied as potential CA for MRI. High relaxivities per chelate, of the order of magnitude 28-38 mM(-1) s(-1) (30 MHz, 25 °C), were attained thanks to simultaneous optimization of the rotational correlation time and of the water exchange rate. Fast local rotational motions of the immobilized chelates around connecting linkers (internal flexibility) still limit the attainable relaxivity. The degree of internal flexibility of the immobilized chelates seems not to be correlated with the length of the connecting linkers. Biodistribution and MRI studies in mice suggest that the in vivo behavior of the gold nanoparticles was determined mainly by size. Small nanoparticles (HD = 3.9 nm) undergo fast renal clearance and avoidance of the RES organs while larger nanoparticles (HD = 4.8 nm) undergo predominantly hepatobiliary excretion. High relaxivities, allied to chelate and nanoparticle stability and fast renal clearance in vivo suggest that functionalized gold nanoparticles hold great potential for further investigation as MRI contrast agents. This study contributes to a better understanding of the effect of linker length on the relaxivity of gold nanoparticles functionalized with Gd(3+) complexes. It is a relevant contribution towards "design rules" for nanostructures functionalized with Gd(3+) chelates as Contrast Agents for MRI and multimodal imaging.This work was financially supported by Fundação para a Ciência e a Tecnologia, Portugal: PhD grant SFRH/BD/63994/2009 to Miguel Ferreira and Sabbatical Grant SFRH/BSAB/1328/2013 to José Martins at Bath University, UK; and Rede Nacional de NMR (REDE/1517/RMN/2005) for the acquisition of the Varian VNMRS 600 NMR spectrometer in Coimbra. T.B.R. was supported by a Marie Curie Fellowship (FP/- PEOPLE-2009-IEF 254380) and an EMBO Fellowship (ALTF 1145-2009). Financial support from Ministerio de Ciencia e Innovación, Spain, projects SAF2011-23622 (S.C.) and CTQ2010-20960-C02-02 (P.L.-L.), and Comunidad de Madrid, Spain, project S2010/BMD-2349 (S.C. and P.L.-L), is also acknowledged. B. Mousavi and L. Helm acknowledge financial support by the Swiss National Science Foundation. This work was carried out in the frame of the COST D38 Action “Metal Based Systems for Molecular Imaging” and COST TD1004 Action “Theranostics Imaging and Therapy”