3,003 research outputs found

    Spatially resolved, substrate-induced rectification in C60 bilayers on copper

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    We demonstrate rectification ratios (RR) of ≳1000 at biases of 1.3 V in bilayers of C60 deposited on copper. Using scanning tunneling spectroscopy and first-principles calculations, we show that the strong coupling between C60 and the Cu(111) surface leads to the metallization of the bottom C60 layer, while the molecular orbitals of the top C60 are essentially unaffected. Due to this substrate-induced symmetry breaking and to a tunneling transport mechanism, the system behaves as a hole-blocking layer, with a spatial dependence of the onset voltage on intra-layer coordination. Together with previous observations of strong electron-blocking character of pentacene/C60 bilayers on Cu(111), this work further demonstrates the potential of strongly hybridized, C60-coated electrodes to harness the electrical functionality of molecular components

    Off-centre supermassive black holes in bright central galaxies

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    Supermassive black holes (SMBHs) are believed to reside at the centre of massive galaxies such as brightest cluster galaxies (BCGs). However, as BCGs experienced numerous galaxy mergers throughout their history, the central BH can be significantly kicked from the central region by these dynamical encounters. By combining the Illustris-TNG300 simulations and orbital integrations, we demonstrate that mergers with satellite galaxies on radial orbits are a main driver for such BH displacements in BCGs. BHs can get ejected to distances varying between a few parsecs to hundreds of kiloparsecs. Our results clearly establish that SMBH offsets are common in BCGs and more precisely a third of our BHs are off-centred at z=0z=0. This orbital offset can be sustained for up to at least 6 Gyr between z=2z=2 and z=0z=0 in half of our BCGs. Since the dense gas reservoirs are located in the central region of galaxies, we argue that the consequences of off-center SMBHs in BCGs are to quench any BH growth and BH feedback.Comment: 7 pages, 7 figures, under revision with MNRA

    Alternating minimization for simultaneous estimation of a latent variable and identification of a linear continuous-time dynamic system

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    We propose an optimization formulation for the simultaneous estimation of a latent variable and the identification of a linear continuous-time dynamic system, given a single input-output pair. We justify this approach based on Bayesian maximum a posteriori estimators. Our scheme takes the form of a convex alternating minimization, over the trajectories and the dynamic model respectively. We prove its convergence to a local minimum which verifies a two point-boundary problem for the (latent) state variable and a tensor product expression for the optimal dynamics

    El amparo arbitral contra las sentencias que resuelven el recurso de anulación de laudo arbitral y el control de los derechos fundamentales

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    En la actualidad, la imposibilidad de ejercer un control constitucional sobre el fondo de la controversia en materia arbitral es sumamente discutible, por este motivo, la presente investigación se abocará a determinar si el precedente vinculante conocido como Caso Minera María Julia que establece la procedencia del amparo arbitral contra las sentencias que resuelven el recurso de anulación de laudo arbitral, garantiza la protección de todos los derechos fundamentales. A efectos de fundamentar nuestra posición, se iniciará por ubicarnos en el contexto de Estado Constitucional de Derecho, para a partir de ese significado desarrollar los conceptos necesarios para entender cómo se deben proteger los derechos fundamentales en el arbitraje y así poder conseguir el análisis correcto del precedente vinculante conocido como Caso Minera María Julia. Posteriormente, se explicara de manera general el precedente vinculante, para poder entender la importancia de su contenido, obligatoriedad y como es que se relaciona con la aplicación del derecho a efectos de poder preveer las consecuencias que puede traer la inobservancia del precedente vinculante conocido como Caso Minera María Julia y el precedente vinculante conocido como Caso Apolonia Colca. Finalmente, se hara un analisis de los precedentes vinculantes conocidos como Caso Cantuarias Salaverry y Caso Apolonia Colca, para dar mayores fundamentos jurídicos a partir de la naturaleza del arbitraje y el criterio de la tesis amplia del amparo. Asimismo, se desarrollaran los principios de interpretación constitucional y los criterios de interpretación de los derechos fundamentales a fin de tener más razones juridicas que determinen que, si se pueden garantizar todos los derechos fundamentales en materia arbitral, a través del precedente vinculante conocido como Caso Minera María Julia.Currently, the impossibility of exercising constitutional control over the merits of the arbitration controversy is highly debatable, for this reason, the present investigation will focus on determining whether the binding precedent known as Caso Minera María Julia establishes the origin of the Arbitral protection against judgments that resolve the annulment of an arbitral award, guarantees the protection of all fundamental rights. In order to base our position, we will begin by locating ourselves in the context of the Constitutional State of Law, and from that meaning develop the necessary concepts to understand how fundamental rights should be protected in arbitration and thus be able to obtain the correct analysis of the binding precedent known as Caso Minera María Julia. Subsequently, the binding precedent will be explained in order to understand the importance of its content, obligation and how it relates to the application of the right to be able to foresee the consequences that the non-observance of the binding precedent known as Case Minera María Julia and the binding precedent known as the Apolonia Colca Case. Finally, an analysis of the binding precedents known as Caso Cantuarias Salaverry and Caso Apolonia Colca will be made, in order to give greater legal grounds from the nature of the arbitration and the criterion of the broad thesis of the amparo. Likewise, the principles of constitutional interpretation and the interpretation criteria of fundamental rights will be developed in order to have more legal reasons that determine if all the fundamental rights in arbitration can be guaranteed, through the binding precedent known as Mining Case María Julia.Tesi

    Validation of an enzyme-linked immunosorbent assay for the quantification of human IgG directed against the repeat region of the circumsporozoite protein of the parasite Plasmodium falciparum.

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    BACKGROUND: Several pre-erythrocytic malaria vaccines based on the circumsporozoite protein (CSP) antigen of Plasmodium falciparum are in clinical development. Vaccine immunogenicity is commonly evaluated by the determination of anti-CSP antibody levels using IgG-based assays, but no standard assay is available to allow comparison of the different vaccines. METHODS: The validation of an anti-CSP repeat region enzyme-linked immunosorbent assay (ELISA) is described. This assay is based on the binding of serum antibodies to R32LR, a recombinant protein composed of the repeat region of P. falciparum CSP. In addition to the original recombinant R32LR, an easy to purify recombinant His-tagged R32LR protein has been constructed to be used as solid phase antigen in the assay. Also, hybridoma cell lines have been generated producing human anti-R32LR monoclonal antibodies to be used as a potential inexhaustible source of anti-CSP repeats standard, instead of a reference serum. RESULTS: The anti-CSP repeats ELISA was shown to be robust, specific and linear within the analytical range, and adequately fulfilled all validation criteria as defined in the ICH guidelines. Furthermore, the coefficient of variation for repeatability and intermediate precision did not exceed 23%. Non-interference was demonstrated for R32LR-binding sera, and the assay was shown to be stable over time. CONCLUSIONS: This ELISA, specific for antibodies directed against the CSP repeat region, can be used as a standard assay for the determination of humoral immunogenicity in the development of any CSP-based P. falciparum malaria vaccine

    Managing HIV as a chronic disease: Using interactive data collection to improve clinical care

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    As South Africa and the rest of the developing world respond to the AIDS crisis, a critical task will be to develop scalable systems for sustainable and effective delivery of antiretroviral (ARV) drugs in a variety of resource-restricted settings. With the emergence, from national governments, the World Health Organization (WHO) and major international donors, of the political will and funding to support treatment programmes, it has become urgent that we consider how ARVs will be delivered. In this review, we consider how ARVs allow us to manage HIV/AIDS as a chronic disease, and the data systems that are required to support this approach to therapy. Southern African Journal of HIV Medicine Vol. 5(4) 2004: 7-1

    Chronic Osteomyelitis

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    Chronic osteomyelitis is a multifaceted bacterial infection with common features. It absolutely requires surgery for remission. The duration and form of concomitant administration of antibiotic agents for adult patients is still based on expert opinion. The traditional recommendation of 6-12weeks of antibiotic therapy, where, for at least the first 2-6weeks, antibiotics should be administered intravenously, is more and more challenged in favor of an oral antibiotic treatment with selected agents from the start. There is no evidence that the total duration of antibiotic therapy for more than 4-6weeks improves outcome, when compared with shorter regimens. Hopefully, the future will show randomized trials in the adult population, allowing optimal timing of surgical and medical therapy and sparing of unnecessary prescription, with concomitant development of antibiotic resistance. External advice from an expert team with combined surgeons and infectious disease physicians may help to reduce antibiotic consumption in a cost-effective wa

    A systematic review and meta-analysis of operative versus non-operative management for first time traumatic anterior shoulder dislocation in young adults

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    Background: The most appropriate management following primary traumatic anterior shoulder dislocation in young adults is unclear. This systematic review and meta-analysis evaluated operative versus non-operative management. The primary outcome measure was re-dislocation rate, in contrast to the often reported ‘recurrent instability’, which includes subjective instability. Methods: Our review was prospectively registered with PROSPERO (CRD42022322600) and reported as per PRISMA guidelines. Selection criteria included mean age of participants between 15 and 25 and minimum follow-up of 1 year. Results: 21 studies meet the inclusion criteria with 5142 patients included. The mean age of patients was 23, with 87% male. There was a median of 54 patients per study and a mean follow up of 46 months per study. The mean re-dislocation rate was 16.08% in the operative group and 24.84% in the non-operative group. In the subgroup meta-analysis, including only RCTs, comparing arthroscopic stabilisation vs non-operative there was an odds ratio of 0.09, strongly favouring intervention. Discussion: This systematic review found the literature available supports surgical intervention in patients under the age of 25, in order to reduce re-dislocation. However, there is a lack of cost-effectiveness data to support these findings, and this should be an area of future research

    Presentation, Clinical Pathology Abnormalities, and Identification of Gastrointestinal Parasites in Camels (Camelus bactrianus and Camelus dromedarius) Presenting to Two North American Veterinary Teaching Hospitals. A Retrospective Study: 1980–2020

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    Old World Camelids (OWC) represent two species (Camelus bactrianus and Camelus dromedarius) with increasing numbers in North America. Gastrointestinal (GI) parasitism is a major cause of clinical disease in camelids and leads to significant economic impacts. Literature reporting on clinical parasitism of camels is localized to India, Africa, and the Middle East, with limited information available on OWCs in North America. Objectives of this study were to report on clinical presentation and diagnostic findings in Camelus bactrianus and Camelus dromedarius with GI parasitism and provide a comparative analysis between geographic regions. Medical records of OWCs presenting to two veterinary teaching hospitals (of the University of Tennessee and University of Wisconsin) were evaluated. Thirty-one camels including 11 Bactrians and six dromedaries (14 species not recorded) were included for the clinical component of this study, reporting on signalment, presenting complaint, and clinical pathology. Anorexia, weight loss, and diarrhea were the most common presenting complaint. Clinical pathology findings included eosinophilia, hypoproteinemia, and hyponatremia. For the second component of this study, a total of 77 fecal parasite examination results were evaluated for parasite identification and regional variation. Trichuris, Capillaria, Strongyloides, Nematodirus, Dictyocaulus, Moniezia, and protozoan parasites (Eimeria, Cryptosporidium, Giardia) were recorded. Strongyle-type eggs predominated, followed by Trichuris and Eimeria spp. There was a statistically significant variation in prevalence of coccidia between the two regions, with fecal examinations from Tennessee more likely to contain Eimeria (P = 0.0193). Clinicians treating camels in North America should recognize anorexia, weight loss, and diarrhea combined with clinical pathologic changes of hypoproteinemia, eosinophilia and hyponatremia as possible indications of GI parasitism. Clinicians should also consider the potential for regional variation to exist for GI parasites of camels in different areas of North America
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