The \Phi^4 quantum field in a scale invariant random metric

We discuss a D-dimensional Euclidean scalar field interacting with a scale invariant quantized metric. We assume that the metric depends on d-dimensional coordinates where d<D. We show that the interacting quantum fields have more regular short distance behaviour than the free fields. A model of a Gaussian metric is discussed in detail. In particular, in the \Phi^4 theory in four dimensions we obtain explicit lower and upper bounds for each term of the perturbation series. It turns out that there is no coupling constant renormalization in the \Phi^4 model in four dimensions. We show that in a particular range of the scale dimension there are models in D=4 without any divergencies

Sufficient Covariate, Propensity Variable and Doubly Robust Estimation

Statistical causal inference from observational studies often requires adjustment for a possibly multi-dimensional variable, where dimension reduction is crucial. The propensity score, first introduced by Rosenbaum and Rubin, is a popular approach to such reduction. We address causal inference within Dawid's decision-theoretic framework, where it is essential to pay attention to sufficient covariates and their properties. We examine the role of a propensity variable in a normal linear model. We investigate both population-based and sample-based linear regressions, with adjustments for a multivariate covariate and for a propensity variable. In addition, we study the augmented inverse probability weighted estimator, involving a combination of a response model and a propensity model. In a linear regression with homoscedasticity, a propensity variable is proved to provide the same estimated causal effect as multivariate adjustment. An estimated propensity variable may, but need not, yield better precision than the true propensity variable. The augmented inverse probability weighted estimator is doubly robust and can improve precision if the propensity model is correctly specified

A Review of the Preclinical and Clinical Efficacy of Remdesivir, Hydroxychloroquine, and Lopinavir-Ritonavir Treatments against COVID-19

In December of 2019, an outbreak of a novel coronavirus flared in Wuhan, the capital city of the Hubei Province, China. The pathogen has been identified as a novel enveloped RNA beta-coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus SARS-CoV-2 is associated with a disease characterized by severe atypical pneumonia known as coronavirus 2019 (COVID-19). Typical symptoms of this disease include cough, fever, malaise, shortness of breath, gastrointestinal symptoms, anosmia, and, in severe cases, pneumonia.1 The high-risk group of COVID-19 patients includes people over the age of 60 years as well as people with existing cardiovascular disease and/or diabetes mellitus. Epidemiological investigations have suggested that the outbreak was associated with a live animal market in Wuhan. Within the first few months of the outbreak, cases were growing exponentially all over the world. The unabated spread of this deadly and highly infectious virus is a health emergency for all nations in the world and has led to the World Health Organization (WHO) declaring a pandemic on March 11, 2020. In this report, we consolidate and review the available clinically and preclinically relevant results emanating from in vitro animal models and clinical studies of drugs approved for emergency use as a treatment for COVID-19, including remdesivir, hydroxychloroquine, and lopinavir-ritonavir combinations. These compounds have been frequently touted as top candidates to treat COVID-19, but recent clinical reports suggest mixed outcomes on their efficacies within the current clinical protocol frameworks

Using Crowdsourcing for Fine-Grained Entity Type Completion in Knowledge Bases

Recent years have witnessed the proliferation of large-scale Knowledge Bases (KBs). However, many entities in KBs have incomplete type information, and some are totally untyped. Even worse, fine-grained types (e.g., BasketballPlayer) containing rich semantic meanings are more likely to be incomplete, as they are more difficult to be obtained. Existing machine-based algorithms use predicates (e.g., birthPlace) of entities to infer their missing types, and they have limitations that the predicates may be insufficient to infer fine-grained types. In this paper, we utilize crowdsourcing to solve the problem, and address the challenge of controlling crowdsourcing cost. To this end, we propose a hybrid machine-crowdsourcing approach for fine-grained entity type completion. It firstly determines the types of some “representative” entities via crowdsourcing and then infers the types for remaining entities based on the crowdsourcing results. To support this approach, we first propose an embedding-based influence for type inference which considers not only the distance between entity embeddings but also the distances between entity and type embeddings. Second, we propose a new difficulty model for entity selection which can better capture the uncertainty of the machine algorithm when identifying the entity types. We demonstrate the effectiveness of our approach through experiments on real crowdsourcing platforms. The results show that our method outperforms the state-of-the-art algorithms by improving the effectiveness of fine-grained type completion at affordable crowdsourcing cost.Peer reviewe

Enhancing thermoelectric properties of single-walled carbon nanotubes using halide compounds at room temperature and above.

Carbon nanotubes (CNTs) are materials with exceptional electrical, thermal, mechanical, and optical properties. Ever since it was demonstrated that they also possess interesting thermoelectric properties, they have been considered a promising solution for thermal energy harvesting. In this study, we present a simple method to enhance their performance. For this purpose, thin films obtained from high-quality single-walled CNTs (SWCNTs) were doped with a spectrum of inorganic and organic halide compounds. We studied how incorporating various halide species affects the electrical conductivity, the Seebeck coefficient, and the Power Factor. Since thermoelectric devices operate under non-ambient conditions, we also evaluated these materials' performance at elevated temperatures. Our research shows that appropriate dopant selection can result in almost fivefold improvement to the Power Factor compared to the pristine material. We also demonstrate that the chemical potential of the starting CNT network determines its properties, which is important for deciphering the true impact of chemical and physical functionalization of such ensembles

Magnetic particles with polymeric shells bearing cholesterol moieties sensitize breast cancer cells to low doses of doxorubicin

One of the promising strategies for improvement of cancer treatment is application of a combination therapy. The aim of this study was to investigate the anticancer activity of nanoformulations containing doxorubicin and iron oxide particles covered with polymeric shells bearing cholesterol moieties. It was postulated that due to high affinity to cell membranes, particles comprising poly(cholesteryl acrylate) can sensitize cancer cells to doxorubicin chemotherapy. The performed analyses revealed that the developed systems are effective against the human breast cancer cell lines MCF-7 and MDA-MB-231 even at low doses of the active compound applied (0.5 µM). Additionally, high compatibility and lack of toxicity of the tested materials against human red blood cells, immune (monocytic THP-1) cells, and cardiomyocyte H9C2(2-1) cells was demonstrated. Synergistic effects observed upon administration of doxorubicin with polymer–iron oxide hybrids comprising poly(cholesteryl acrylate) may provide an opportunity to limit toxicity of the drug and to improve its therapeutic efficiency at the same time

Differences in genotype and virulence among four multidrug-resistant <i>Streptococcus pneumoniae</i> isolates belonging to the PMEN1 clone

We report on the comparative genomics and characterization of the virulence phenotypes of four &lt;i&gt;S. pneumoniae&lt;/i&gt; strains that belong to the multidrug resistant clone PMEN1 (Spain&lt;sup&gt;23F&lt;/sup&gt; ST81). Strains SV35-T23 and SV36-T3 were recovered in 1996 from the nasopharynx of patients at an AIDS hospice in New York. Strain SV36-T3 expressed capsule type 3 which is unusual for this clone and represents the product of an in vivo capsular switch event. A third PMEN1 isolate - PN4595-T23 - was recovered in 1996 from the nasopharynx of a child attending day care in Portugal, and a fourth strain - ATCC700669 - was originally isolated from a patient with pneumococcal disease in Spain in 1984. We compared the genomes among four PMEN1 strains and 47 previously sequenced pneumococcal isolates for gene possession differences and allelic variations within core genes. In contrast to the 47 strains - representing a variety of clonal types - the four PMEN1 strains grouped closely together, demonstrating high genomic conservation within this lineage relative to the rest of the species. In the four PMEN1 strains allelic and gene possession differences were clustered into 18 genomic regions including the capsule, the blp bacteriocins, erythromycin resistance, the MM1-2008 prophage and multiple cell wall anchored proteins. In spite of their genomic similarity, the high resolution chinchilla model was able to detect variations in virulence properties of the PMEN1 strains highlighting how small genic or allelic variation can lead to significant changes in pathogenicity and making this set of strains ideal for the identification of novel virulence determinant

Conscious sedation for transcatheter implantation of atrial septal occluders with two- and three-dimensional transoesophageal echocardiography guidance — a feasibility and safety study

Background: General anaesthesia may have negative impact on patient mortality and morbidity, as well as overall procedure costs, in atrial septal occluder (ASO) implantation. Aim: We sought to evaluate the safety, efficacy, and feasibility of conscious sedation for transcatheter implantation of ASOs. Methods: A total of 122 patients referred for transcatheter implantation of ASO were included. Mean patient age was 51 ± 15 years, and 43 (35%) patients were male. The initial dose of midazolam was 2 mg and fentanyl dose was 25 μg. Additional doses of midazolam and fentanyl were administered, if necessary. Patient responsiveness was assessed every 10 min, and the sedatives doses were titrated in order not to exceed grade 3 sedation in the Ramsey scale. Results: Atrial septal occluders were successfully implanted in the majority of patients (98.4%). In two (1.6%) cases the proce­dure failed because of too small patent foramen ovale (PFO) diameter (n = 1, 0.8%) or device instability (n = 1, 0.8%). The mean duration of procedure was 47.6 ± 28.4 min and was similar for ASD and PFO closure (p = 0.522). The overall mean dose of midazolam was 4.7 ± 2.2 mg (63.9 ± 32.5 μg/kg) and fentanyl was 30.0 ± 11.9 μg (0.43 ± 0.17 μg/kg). Median entrance dose of radiation at the patient plane was 25 (interquartile range: 16–57) mGy, and did not differ between ASD and PFO procedures (p = 0.614). The majority of patients were free of complications (91.0%). The following early complications were observed: transient ischaemic attack (n = 2, 1.6%), supraventricular arrhythmias (n = 4, 3.3%), left atrial thrombus formation (n = 1, 0.8%), symptomatic bradycardia (n = 1, 0.8%), and femoral venous bleeding (n = 5, 4.1%). After mean follow-up of 386 days residual shunt was observed in eight (6.6%) patients. Conclusions: Conscious sedation for transcatheter implantation of ASO is a feasible, safe, and efficient technique, allowing successful PFO and ASD closure in the majority of patients.Background: General anaesthesia may have negative impact on patient mortality and morbidity, as well as overall procedure costs, in atrial septal occluder (ASO) implantation. Aim: We sought to evaluate the safety, efficacy, and feasibility of conscious sedation for transcatheter implantation of ASOs. Methods: A total of 122 patients referred for transcatheter implantation of ASO were included. Mean patient age was 51 ± 15 years, and 43 (35%) patients were male. The initial dose of midazolam was 2 mg and fentanyl dose was 25 μg. Additional doses of midazolam and fentanyl were administered, if necessary. Patient responsiveness was assessed every 10 min, and the sedatives doses were titrated in order not to exceed grade 3 sedation in the Ramsey scale. Results: Atrial septal occluders were successfully implanted in the majority of patients (98.4%). In two (1.6%) cases the proce­dure failed because of too small patent foramen ovale (PFO) diameter (n = 1, 0.8%) or device instability (n = 1, 0.8%). The mean duration of procedure was 47.6 ± 28.4 min and was similar for ASD and PFO closure (p = 0.522). The overall mean dose of midazolam was 4.7 ± 2.2 mg (63.9 ± 32.5 μg/kg) and fentanyl was 30.0 ± 11.9 μg (0.43 ± 0.17 μg/kg). Median entrance dose of radiation at the patient plane was 25 (interquartile range: 16–57) mGy, and did not differ between ASD and PFO procedures (p = 0.614). The majority of patients were free of complications (91.0%). The following early complications were observed: transient ischaemic attack (n = 2, 1.6%), supraventricular arrhythmias (n = 4, 3.3%), left atrial thrombus formation (n = 1, 0.8%), symptomatic bradycardia (n = 1, 0.8%), and femoral venous bleeding (n = 5, 4.1%). After mean follow-up of 386 days residual shunt was observed in eight (6.6%) patients. Conclusions: Conscious sedation for transcatheter implantation of ASO is a feasible, safe, and efficient technique, allowing successful PFO and ASD closure in the majority of patients

Graphene Oxide Hybrid with Sulfur–Nitrogen Polymer for High-Performance Pseudocapacitors

Toward the introduction of fast faradaic pseudocapacitive behavior and the increase of the specific capacitance of carbon-based electrodes, we covalently functionalized graphene oxide with a redox active thiourea-formaldehyde polymer, yielding a multifunctional hybrid system. The multiscale physical and chemical characterization of the novel 3-dimensional hybrid revealed high material porosity with high specific surface area (402 m2 g–1) and homogeneous element distribution. The presence of multiple functional groups comprising sulfur, nitrogen, and oxygen provide additional contribution of Faradaic redox reaction in supercapacity performance, leading to a high effective electrochemical pseudocapacitance. Significantly, our graphene-based 3-dimensional thiourea-formaldehyde hybrid exhibited specific capacitance as high as 400 F g–1, areal capacitance of 160 mF cm–2, and an energy density of 11.1 mWh cm–3 at scan rate of 1 mV s–1 with great capacitance retention (100%) after 5000 cycles at scan rate of 100 mV s–1