Towards a Top-K SPARQL Query Benchmark Generator

The research on optimization of top-k SPARQL query would largely benefit from the establishment of a benchmark that allows comparing different approaches. For such a benchmark to be meaningful, at least two requirements should hold: 1) the benchmark should resemble reality as much as possible, and 2) it should stress the features of the topk SPARQL queries both from a syntactic and performance perspective. In this paper we propose Top-k DBPSB: an extension of the DBpedia SPARQL benchmark (DBPSB), a benchmark known to resemble reality, with the capabilities required to compare SPARQL engines on top-k queries.Web Information System

Effect of the Surface Chemical Composition and of Added Metal Cation Concentration on the Stability of Metal Nanoparticles Synthesized by Pulsed Laser Ablation in Water

Metal nanoparticles (NPs) made of gold, silver, and platinum have been synthesized by means of pulsed laser ablation in liquid aqueous solution. Independently from the metal nature, all NPs have an average diameter of 10 ± 5 nm. The ζ-potential values are: −62 ± 7 mV for gold, −44 ± 2 mV for silver and −58 ± 3 for platinum. XPS analysis demonstrates the absence of metal oxides in the case of gold and silver NPs. In the case of platinum NPs, 22% of the particle surface is ascribed to platinum oxidized species. This points to a marginal role of the metal oxides in building the negative charge that stabilizes these colloidal suspensions. The investigation of the colloidal stability of gold NPs in the presence of metal cations shows these NPs can be destabilized by trace amounts of selected metal ions. The case of Ag+ is paradigmatic since it is able to reduce the NP ζ-potential and to induce coagulation at concentrations as low as 3 μM, while in the case of K+ the critical coagulation concentration is around 8 mM. It is proposed that such a huge difference in destabilization power between monovalent cations can be accounted for by the difference in the reduction potential

Epitope-engineered human hematopoietic stem cells are shielded from CD123-targeted immunotherapy

Targeted eradication of transformed or otherwise dysregulated cells using monoclonal antibodies (mAb), antibody-drug conjugates (ADC), T cell engagers (TCE), or chimeric antigen receptor (CAR) cells is very effective for hematologic diseases. Unlike the breakthrough progress achieved for B cell malignancies, there is a pressing need to find suitable antigens for myeloid malignancies. CD123, the interleukin-3 (IL-3) receptor alpha-chain, is highly expressed in various hematological malignancies, including acute myeloid leukemia (AML). However, shared CD123 expression on healthy hematopoietic stem and progenitor cells (HSPCs) bears the risk for myelotoxicity. We demonstrate that epitope-engineered HSPCs were shielded from CD123-targeted immunotherapy but remained functional, while CD123-deficient HSPCs displayed a competitive disadvantage. Transplantation of genome-edited HSPCs could enable tumor-selective targeted immunotherapy while rebuilding a fully functional hematopoietic system. We envision that this approach is broadly applicable to other targets and cells, could render hitherto undruggable targets accessible to immunotherapy, and will allow continued posttransplant therapy, for instance, to treat minimal residual disease (MRD)

Taming velocity and variety simultaneously in big data with stream reasoning tutorial

Many "big data" applications must tame velocity (processing data in-motion) and variety (processing many different types of data) simultaneously. The research on knowledge representation and reasoning has focused on the variety of data, devising data representation and processing techniques that promote integration and reasoning on available data to extract implicit information. On the other hand, the event and stream processing community has focused on the velocity of data, producing systems that efficiently operate on streams of data on-the-fly according to pre-deployed processing rules or queries. Several recent works explore the synergy between stream processing and reasoning to fully capture the requirements of modern data intensive applications, thus giving birth to the research domain of stream reasoning. This tutorial paper offers an overview of the theoretical and technological achievements in stream reasoning, highlighting the key benefits and limitations of existing approaches, and discussing the open challenges and the opportunities for future research. The paper mainly targets researchers and practitioners in the area of event and stream processing. The paper aims to stimulate the discussion on stream reasoning and to further promote the integration of reasoning techniques within event and stream processing systems in three ways: (i) by presenting an active research domain, where researchers on event and stream processing can apply their expertise; (ii) by discussing techniques and technologies that can help advancing the state of the art in event and stream processing; (iii) by identifying the open problems in the field of stream reasoning, and drawing attention to promising research directions

Nanoparticle Enhanced Laser Induced Breakdown Spectroscopy (NELIBS), a first review

In this paper, the promising variant of the Laser Induced Breakdown Spectroscopy (LIBS) technique, namely Nanoparticle - Enhanced LIBS (NELIBS) is described. The underlying mechanisms responsible for NELIBS are described. This is done by presenting both the properties of metallic particles interacting with high-energy laser radiation and the mechanisms of laser ablation enabled by the presence of nanoparticles. Clarifications are also made about the sample preparation for NELIBS in particular about how to reach the optimal surface concentration of nanoparticles. NELIBS applications on different kinds of samples are also described such as metals, transparent samples, fresh samples and liquids including biological fluids

Plasma Parameters During Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy (NELIBS) in the Presence of Nanoparticle-Protein Conjugates

Nanoparticle-enhanced laser-induced breakdown spectroscopy (NELIBS) is an optical emission technique based on the laser-induced plasma (LIP) on a sample after the deposition of plasmonic nanoparticles (NPs) on its surface. The employment of the NPs allows an enhancement of the signal with respect to the one obtained with the conventional laser-induced breakdown spectroscopy (LIBS) enabling an extremely high sensitivity and very low limits of detection compared with the LIBS performance. Recently, NELIBS was used for monitoring the NP protein corona formation. As a matter of fact, the NPs in the presence of proteins adsorbed on the surface change their surface properties, therefore the sensing of protein corona formation was possible because of the strong dependence of NELIBS effects on the NP organization on the substrate, which in turn is deeply affected by the surface properties of the NPs. A correlation was found between NELIBS enhancement and the structure of the NP-protein conjugate in terms of protein content absorbed on the NP surface. An interesting question that was not yet exploited regards the role of LIP during the NELIBS when the NPs are covered with proteins. Since the presence of organic matter can strongly quench the LIP emission, the study of the LIP properties during protein corona sensing by NELIBS is of interest for two main reasons: (i) to understand whether the plasma parameters can vary in the presence of proteins adsorbed on the NP surface and (ii) to investigate how and if the plasma parameters themselves can influence the NELIBS processes. With this aim, the study of plasma parameters, i.e., electron densities and temperatures, during the sensing of NP protein corona by NELIBS is presented and discussed. The NPs used during these experiments were ultrapure gold NPs (AuNPs) produced by pulsed laser ablation in liquid, which are stable without any stabilizer. The human serum albumin protein is used to form AuNP-protein conjugates further deposited on a titanium target in NELIBS measurements. Dynamic light scattering, surface plasmon resonance spectroscopy, and laser Doppler electrophoresis for zeta-potential determination were employed to monitor the protein coverage of NP surface in the conjugate solutions before the NELIBS measurements