Tunable Surface Properties of Aluminum Oxide Nanoparticles from Highly Hydrophobic to Highly Hydrophilic

The formation of materials with tunable wettability is important for applications ranging from antifouling to waterproofing surfaces. We report the use of various low-cost and nonhazardous hydrocarbon materials to tune the surface properties of aluminum oxide nanoparticles (NPs) from superhydrophilic to superhydrophobic through covalent functionalization. The hydrocarbon surfaces are compared with a fluorinated surface for wettability and surface energy properties. The role of NPs’ hydrophobicity on their dynamic interfacial behavior at the oil–water interface and their ability to form stable emulsions is also explored. The spray-coated NPs provide textured surfaces (regardless of functionality), with water contact angles (θ) of 10–150° based on their surface functionality. The superhydrophobic NPs are able to reduce the interfacial tension of various oil–water interfaces by behaving as surfactants

Binding of quinazolinones to c-KIT G-quadruplex; an interplay between hydrogen bonding and π-π stacking

Stabilization of G-quadruplex structures in the c-KIT promoter with the aid of ligands has become an area of great interest in potential cancer therapeutics. Understanding the binding process between ligands and G-quadruplex is essential for a discovery of selective ligands with high binding affinity to G-quadruplex. In the present work, binding mechanisms of 4-quinazolinones to c-KIT G-quadruplex were investigated theoretically by means of molecular dynamics (MD) simulations. To explore the binding affinity of ligands, binding free energy calculations were performed using the molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method. We demonstrate that the key interactions in G-quadruplex-ligand complexes are π-π stacking and hydrogen bond interactions. However, neither of these two interactions alone determines the stability of the G-quadruplex-ligand complexes; rather, it is the result of an intricate interplay between the two. To further examine the nature of the binding, a free energy decomposition analysis at residue level was carried out. The results clearly demonstrate the crucial roles of two hot spot residues (DG4 and DG8) for the binding of ligands to c-KIT G-quadruplex, and highlight the importance of the planar aromatic moiety of ligands in G-quadruplex stabilization via π-π stacking interactions. Our study can assist in the design of new derivatives of 4-quinazolinone with high binding affinity for c-KIT G-quadruplex

Branched Hydrocarbon Low Surface Energy Materials for Superhydrophobic Nanoparticle Derived Surfaces

International audienceWe present a new class of superhydrophobic surfaces created from low-cost and easily synthesized aluminum oxide nanoparticles functionalized carboxylic acids having highly branched hydrocarbon (HC) chains. These branched chains are new low surface energy materials (LSEMs) which can replace environmentally hazardous and expensive fluorocarbons (FCs). Regardless of coating method and curing temperature, the resulting textured surfaces develop water contact angles (θ) of ~155° and root-mean-square roughnesses (Rq) ≈ 85 nm, being comparable with equivalent FC functionalized surfaces (θ = 157º and Rq = 100 nm). The functionalized nanoparticles may be coated onto a variety of substrates to generate different superhydrophobic materials

White, Man, and Highly Followed: Gender and Race Inequalities in Twitter

Social media is considered a democratic space in which people connect and interact with each other regardless of their gender, race, or any other demographic factor. Despite numerous efforts that explore demographic factors in social media, it is still unclear whether social media perpetuates old inequalities from the offline world. In this paper, we attempt to identify gender and race of Twitter users located in U.S. using advanced image processing algorithms from Face++. Then, we investigate how different demographic groups (i.e. male/female, Asian/Black/White) connect with other. We quantify to what extent one group follow and interact with each other and the extent to which these connections and interactions reflect in inequalities in Twitter. Our analysis shows that users identified as White and male tend to attain higher positions in Twitter, in terms of the number of followers and number of times in user's lists. We hope our effort can stimulate the development of new theories of demographic information in the online space.Comment: In Proceedings of the IEEE/WIC/ACM International Conference on Web Intelligence (WI'17). Leipzig, Germany. August 201

Single-cell RNA sequencing of liver fine-needle aspirates captures immune diversity in the blood and liver in chronic hepatitis B patients

Background and Aims: HBV infection is restricted to the liver, where it drives exhaustion of virus-specific T and B cells and pathogenesis through dysregulation of intrahepatic immunity. Our understanding of liver-specific events related to viral control and liver damage has relied almost solely on animal models, and we lack useable peripheral biomarkers to quantify intrahepatic immune activation beyond cytokine measurement. Our objective was to overcome the practical obstacles of liver sampling using fine-needle aspiration and develop an optimized workflow to comprehensively compare the blood and liver compartments within patients with chronic hepatitis B using single-cell RNA sequencing. Approach and Results: We developed a workflow that enabled multi-site international studies and centralized single-cell RNA sequencing. Blood and liver fine-needle aspirations were collected, and cellular and molecular captures were compared between the Seq-Well S3 picowell-based and the 10× Chromium reverse-emulsion droplet–based single-cell RNA sequencing technologies. Both technologies captured the cellular diversity of the liver, but Seq-Well S3 effectively captured neutrophils, which were absent in the 10× dataset. CD8 T cells and neutrophils displayed distinct transcriptional profiles between blood and liver. In addition, liver fine-needle aspirations captured a heterogeneous liver macrophage population. Comparison between untreated patients with chronic hepatitis B and patients treated with nucleoside analogs showed that myeloid cells were highly sensitive to environmental changes while lymphocytes displayed minimal differences. Conclusions: The ability to electively sample and intensively profile the immune landscape of the liver, and generate high-resolution data, will enable multi-site clinical studies to identify biomarkers for intrahepatic immune activity in HBV and beyond.</p

Clinical practice guidelines for the diagnosis and surveillance of BAP1 tumour predisposition syndrome

BRCA1-associated protein-1 (BAP1) is a recognised tumour suppressor gene. Germline BAP1 pathogenic/likely pathogenic variants are associated with predisposition to multiple tumours, including uveal melanoma, malignant pleural and peritoneal mesothelioma, renal cell carcinoma and specific non-malignant neoplasms of the skin, as part of the autosomal dominant BAP1-tumour predisposition syndrome. The overall lifetime risk for BAP1 carriers to develop at least one BAP1-associated tumour is up to 85%, although due to ascertainment bias, current estimates of risk are likely to be overestimated. As for many rare cancer predisposition syndromes, there is limited scientific evidence to support the utility of surveillance and, therefore, management recommendations for BAP1 carriers are based on expert opinion. To date, European recommendations for BAP1 carriers have not been published but are necessary due to the emerging phenotype of this recently described syndrome and increased identification of BAP1 carriers via large gene panels or tumour sequencing. To address this, the Clinical Guideline Working Group of the CanGene-CanVar project in the United Kingdom invited European collaborators to collaborate to develop guidelines to harmonize surveillance programmes within Europe. Recommendations with respect to BAP1 testing and surveillance were achieved following literature review and Delphi survey completed by a core group and an extended expert group of 34 European specialists including Geneticists, Ophthalmologists, Oncologists, Dermatologists and Pathologists. It is recognised that these largely evidence-based but pragmatic recommendations will evolve over time as further data from research collaborations informs the phenotypic spectrum and surveillance outcomes.</p

Resolving catastrophic error bursts from cosmic rays in large arrays of superconducting qubits

Scalable quantum computing can become a reality with error correction, provided coherent qubits can be constructed in large arrays. The key premise is that physical errors can remain both small and sufficiently uncorrelated as devices scale, so that logical error rates can be exponentially suppressed. However, energetic impacts from cosmic rays and latent radioactivity violate both of these assumptions. An impinging particle ionizes the substrate, radiating high energy phonons that induce a burst of quasiparticles, destroying qubit coherence throughout the device. High-energy radiation has been identified as a source of error in pilot superconducting quantum devices, but lacking a measurement technique able to resolve a single event in detail, the effect on large scale algorithms and error correction in particular remains an open question. Elucidating the physics involved requires operating large numbers of qubits at the same rapid timescales as in error correction, exposing the event's evolution in time and spread in space. Here, we directly observe high-energy rays impacting a large-scale quantum processor. We introduce a rapid space and time-multiplexed measurement method and identify large bursts of quasiparticles that simultaneously and severely limit the energy coherence of all qubits, causing chip-wide failure. We track the events from their initial localised impact to high error rates across the chip. Our results provide direct insights into the scale and dynamics of these damaging error bursts in large-scale devices, and highlight the necessity of mitigation to enable quantum computing to scale

The Natural Cytotoxicity Receptor 1 Contribution to Early Clearance of Streptococcus pneumoniae and to Natural Killer-Macrophage Cross Talk

Natural killer (NK) cells serve as a crucial first line of defense against tumors, viral and bacterial infections. We studied the involvement of a principal activating natural killer cell receptor, natural cytotoxicity receptor 1 (NCR1), in the innate immune response to S. pneumoniae infection. Our results demonstrate that the presence of the NCR1 receptor is imperative for the early clearance of S. pneumoniae. We tied the ends in vivo by showing that deficiency in NCR1 resulted in reduced lung NK cell activation and lung IFNγ production at the early stages of S. pneumoniae infection. NCR1 did not mediate direct recognition of S. pneumoniae. Therefore, we studied the involvement of lung macrophages and dendritic cells (DC) as the mediators of NK-expressed NCR1 involvement in response to S. pneumoniae. In vitro, wild type BM-derived macrophages and DC expressed ligands to NCR1 and co-incubation of S. pneumoniae-infected macrophages/DC with NCR1-deficient NK cells resulted in significantly lesser IFNγ levels compared to NCR1-expressing NK cells. In vivo, ablation of lung macrophages and DC was detrimental to the early clearance of S. pneumoniae. NCR1-expressing mice had more potent alveolar macrophages as compared to NCR1-deficient mice. This result correlated with the higher fraction of NCR1-ligandhigh lung macrophages, in NCR1-expressing mice, that had better phagocytic activity compared to NCR1-liganddull macrophages. Overall, our results point to the essential contribution of NK-expressed NCR1 in early response to S. pneumoniae infection and to NCR1-mediated interaction of NK and S. pneumoniae infected-macrophages and -DC

Readout of a quantum processor with high dynamic range Josephson parametric amplifiers

We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device is matched to the 50 $\Omega$ environment with a Klopfenstein-taper impedance transformer and achieves a bandwidth of 250-300 MHz, with input saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used to benchmark these devices, providing a calibration for readout power, an estimate of amplifier added noise, and a platform for comparison against standard impedance matched parametric amplifiers with a single dc-SQUID. We find that the high power rf-SQUID array design has no adverse effect on system noise, readout fidelity, or qubit dephasing, and we estimate an upper bound on amplifier added noise at 1.6 times the quantum limit. Lastly, amplifiers with this design show no degradation in readout fidelity due to gain compression, which can occur in multi-tone multiplexed readout with traditional JPAs.Comment: 9 pages, 8 figure

Measurement-Induced State Transitions in a Superconducting Qubit: Within the Rotating Wave Approximation

Superconducting qubits typically use a dispersive readout scheme, where a resonator is coupled to a qubit such that its frequency is qubit-state dependent. Measurement is performed by driving the resonator, where the transmitted resonator field yields information about the resonator frequency and thus the qubit state. Ideally, we could use arbitrarily strong resonator drives to achieve a target signal-to-noise ratio in the shortest possible time. However, experiments have shown that when the average resonator photon number exceeds a certain threshold, the qubit is excited out of its computational subspace, which we refer to as a measurement-induced state transition. These transitions degrade readout fidelity, and constitute leakage which precludes further operation of the qubit in, for example, error correction. Here we study these transitions using a transmon qubit by experimentally measuring their dependence on qubit frequency, average photon number, and qubit state, in the regime where the resonator frequency is lower than the qubit frequency. We observe signatures of resonant transitions between levels in the coupled qubit-resonator system that exhibit noisy behavior when measured repeatedly in time. We provide a semi-classical model of these transitions based on the rotating wave approximation and use it to predict the onset of state transitions in our experiments. Our results suggest the transmon is excited to levels near the top of its cosine potential following a state transition, where the charge dispersion of higher transmon levels explains the observed noisy behavior of state transitions. Moreover, occupation in these higher energy levels poses a major challenge for fast qubit reset