Software for doing computations in graded Lie algebras

We introduce the Macaulay2 package GradedLieAlgebras for doing computations in graded Lie algebras presented by generators and relations.Comment: 5 page

Simulation of primary particle size distributions in a premixed ethylene stagnation flame

Numerical simulation of soot formation in a laminar premixed burner-stabilized ethylene stagnation flame was performed with a detailed population balance model (DPBM) capable of tracking full structural details of aggregates as well as their chemical composition. A thorough parametric sensitivity study was carried out to understand the influence of individual sooting processes on the computed primary particle size distributions (PPSDs). The rate of production of pyrene, coagulation efficiency and surface growth rate were found to have significant effects on the computed PPSDs. Besides, we found that the instantaneous sintering between small primary particles (PP) can affect the computed PPSDs drastically while sintering between large PPs within aggregates only had mild effects. For an ethylene premixed flame with stagnation plate height being 1.2 cm (Combust. Flame, 198:428-435, 2018), good agreement was obtained between both the computed and measured PPSD and fractal dimension, which supports the current mechanisms contributing to the evolution of PPs, i.e. nucleation, coagulation, surface growth and sintering. Moreover, time scale analysis for individual sooting processes was performed to determine the dominant particle processes at different periods of time, which helped explain the evolution of soot morphology

A radiomics model based on preoperative gadoxetic acid–enhanced magnetic resonance imaging for predicting post-hepatectomy liver failure in patients with hepatocellular carcinoma

BackgroundPost-hepatectomy liver failure (PHLF) is a fatal complication after liver resection in patients with hepatocellular carcinoma (HCC). It is of clinical importance to estimate the risk of PHLF preoperatively.AimsThis study aimed to develop and validate a prediction model based on preoperative gadoxetic acid–enhanced magnetic resonance imaging to estimate the risk of PHLF in patients with HCC.MethodsA total of 276 patients were retrospectively included and randomly divided into training and test cohorts (194:82). Clinicopathological variables were assessed to identify significant indicators for PHLF prediction. Radiomics features were extracted from the normal liver parenchyma at the hepatobiliary phase and the reproducible, robust and non-redundant ones were filtered for modeling. Prediction models were developed using clinicopathological variables (Clin-model), radiomics features (Rad-model), and their combination.ResultsThe PHLF incidence rate was 24% in the whole cohort. The combined model, consisting of albumin–bilirubin (ALBI) score, indocyanine green retention test at 15 min (ICG-R15), and Rad-score (derived from 16 radiomics features) outperformed the Clin-model and the Rad-model. It yielded an area under the receiver operating characteristic curve (AUC) of 0.84 (95% confidence interval (CI): 0.77–0.90) in the training cohort and 0.82 (95% CI: 0.72–0.91) in the test cohort. The model demonstrated a good consistency by the Hosmer–Lemeshow test and the calibration curve. The combined model was visualized as a nomogram for estimating individual risk of PHLF.ConclusionA model combining clinicopathological risk factors and radiomics signature can be applied to identify patients with high risk of PHLF and serve as a decision aid when planning surgery treatment in patients with HCC

Suppression of the Hepatitis C viral load by Phyllanthus niruri extracts

Gemstone Team ANTIDOTEHepatitis C virus (HCV) is a public health crisis, affecting over 170 million people by 2011. Conventional treatment, interferon alpha with ribavirin, can often be ineffective and may lead to severe side effects, and this lack of effective treatment poses significant challenges to patients, healthcare providers, and public health officials. As a result, our team investigated the therapeutic potential of medicinal plant extracts from Phyllanthus niruri as an alternative treatment for HCV. Molecular barcoding of chloroplast genes rbcl and matk was used to document the genetic identity of our plants. Phytochemicals were then extracted from dried plant material to isolate potential active compounds. We applied the extraction products to HCV-infected cell lines, specifically Huh7.5 liver cancer cells with J6JFH virus, to determine their effects on viral load and cell toxicity. Our extracts significantly decrease the number of viral copies per cell with no significant toxicity. Viral load suppression was strongest 24 hours after treatment. This effect either declined (extracts 3 and 4) or was sustained (extracts 1 and 2) over time. Extract 4 at 1 μg/ml at 24 hours and 5 at 10 μg/ml at 96 hours reached near 100% suppression, demonstrating significant potent effect comparable to interferon-alpha, but the effect of Extract 4 is not sustained. It also demonstrates different extracts may exhibit different kinetics, suggesting different mechanisms of action. Overall, our study serves as a building block to develop novel treatments and contributes to the discovery of alternative drug options for HCV patients

Guinea Pig Model for Evaluating the Potential Public Health Risk of Swine and Avian Influenza Viruses

BACKGROUND: The influenza viruses circulating in animals sporadically transmit to humans and pose pandemic threats. Animal models to evaluate the potential public health risk potential of these viruses are needed. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the guinea pig as a mammalian model for the study of the replication and transmission characteristics of selected swine H1N1, H1N2, H3N2 and avian H9N2 influenza viruses, compared to those of pandemic (H1N1) 2009 and seasonal human H1N1, H3N2 influenza viruses. The swine and avian influenza viruses investigated were restricted to the respiratory system of guinea pigs and shed at high titers in nasal tracts without prior adaptation, similar to human strains. None of the swine and avian influenza viruses showed transmissibility among guinea pigs; in contrast, pandemic (H1N1) 2009 virus transmitted from infected guinea pigs to all animals and seasonal human influenza viruses could also horizontally transmit in guinea pigs. The analysis of the receptor distribution in the guinea pig respiratory tissues by lectin histochemistry indicated that both SAα2,3-Gal and SAα2,6-Gal receptors widely presented in the nasal tract and the trachea, while SAα2,3-Gal receptor was the main receptor in the lung. CONCLUSIONS/SIGNIFICANCE: We propose that the guinea pig could serve as a useful mammalian model to evaluate the potential public health threat of swine and avian influenza viruses

Comparison of Imaging Radar Configurations for Roadway Inspection and Characterization

This paper investigates the performance of a wide variety of radar imaging modes, such as nadir-looking B-scan, or side-looking synthetic aperture radar tomographic acquisitions, performed in both back- and forward-scattering geometries, for the inspection and characterization of roadways. Nadir-looking B-scan corresponds to a low-complexity mode exploiting the direct return from the response, whereas side-looking configurations allow the utilization of angular and polarimetric diversity in order to analyze advanced features. The main objective of this paper is to evaluate the ability of each configuration, independently of aspects related to operational implementation, to discriminate and localize shallow underground defects in the wearing course of roadways, and to estimate key geophysical parameters, such as roughness and dielectric permittivity. Campaign measurements are conducted using short-range radar stepped-frequency continuous-waveform (SFCW) devices operated in the C and X bands, at the pavement fatigue carousel of Université Gustave Eiffel, over debonded areas with artificial defects. The results indicate the great potential of the newly proposed forward-scattering tomographic configuration for detecting slight defects and characterizing roadways. Case studies, performed in the presence of narrow horizontal heterogeneities which cannot be detected using classical B-scan, show that both the coherent integration along an aperture using the back-projection algorithm, and the exploitation of scattering mechanisms specific to the forward-looking bistatic geometry, allows anomalous echoes to be detected and further characterized, confirming the efficacy of radar imaging techniques in such applications

The Effects of the Downstream Contraction Ratio of Organ-Pipe Nozzle on the Pressure Oscillations of Self-Resonating Waterjets

Self-resonating waterjets (SRWJs) are being widely used in the fields of energy exploitation, due to the significantly increased penetration rate of roller bits in deep-hole drilling. To further improve the impact and erosion abilities of SRWJs, the effects of the downstream contraction ratio of organ-pipe nozzle on the axial pressure oscillations were experimentally studied. The axial pressure oscillation peak and amplitude were used to evaluate the effects under two inlet pressures and various standoff distances. The results show that the downstream contraction ratio can affect the development trends of the pressure oscillations and determines the values of the peaks and amplitudes. Under the experimental conditions, 2.5 is the ratio that leads to the maximum peaks and amplitudes at almost all the testing standoff distances, while the ratio of 2 always results in the minimum ones. The development trend of the pressure oscillation peak for the ratio of 3.5 has a great change at an inlet pressure of 20 MPa. Generally, the relative pressure oscillations are more violent at an inlet pressure of 10 MPa, which is regardless of the contraction ratio. This study helps provide a guideline for determining the physical parameters required in the fabrication of organ-pipe nozzles used for deep-hole drilling

Measurement of sub-3 nm flame-generated particles using butanol CPCs in boosted conditions

International audienceWhile condensation particle counters (CPCs) are routinely used to measure particle number concentrations in the size range from 3 to 1000 nm, the detection efficiency for sub-3 nm particles remains relatively poor. In this study, the performance of an ultrafine butanol based CPC for the measurement of alkyl ammonium halide ions, flame-generated particles of titanium dioxide (TiO2) and soot is evaluated. Homogenous nucleation of butanol vapors, and detection efficiency of THAB ions are systematically evaluated for a range of saturator temperatures (39–45 °C) and capillary flow rates (30–70 sccm). The optimal operating conditions with minimal background interferences was found to be a saturator temperature of 45 °C and capillary flow rate of 70 sccm. Flame generated particles of TiO2 and soot were activated more readily than the alkyl ammonium halide salts of similar mobility diameters, especially in the below 1.6 nm mobility size range, whereas above 1.6 nm the detection efficiency is independent of particle material, but depends on particle size. The negative charge on the particles is found to promote activation with butanol vapors leading to higher activation efficiencies than positively charged particles. Finally, the importance of butanol as a working fluid, and its calibration for precise measurement of sub-3 nm particles is discussed. This will enable researchers to perform experiments using a ‘conventional’ CPC with boosted conditions for the understanding of early stages of particle formation and growth in different aerosol reactors

Analysis of In Vivo Transcriptome of Intracellular Bacterial Pathogen Salmonella enterica serovar Typhmurium Isolated from Mouse Spleen

Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important intracellular pathogen that poses a health threat to humans. This study tries to clarify the mechanism of Salmonella survival and reproduction in the host. In this study, high-throughput sequencing analysis was performed on RNA extracted from the strains isolated from infected mouse spleens and an S. Typhimurium reference strain (ATCC 14028) based on the BGISEQ-500 platform. A total of 1340 significant differentially expressed genes (DEGs) were screened. Functional annotation revealed DEGs associated with regulation, metabolism, transport and binding, pathogenesis, and motility. Through data mining and literature retrieval, 26 of the 58 upregulated DEGs (FPKM > 10) were not reported to be related to the adaptation to intracellular survival and were classified as candidate key genes (CKGs) for survival and proliferation in vivo. Our data contribute to our understanding of the mechanisms used by Salmonella to regulate virulence gene expression whilst replicating inside mammalian cells

Characteristics and Epidemiological Investigation of Paratuberculosis in Dairy Cattle in Tai’an, China

Paratuberculosis, a chronic and sometimes fatal disease of ruminants, is caused by Mycobacterium avium subsp. paratuberculosis (MAP). In this study, we examined paratuberculosis cases among 2–4-year-old dairy cows at farms in Shandong Province, China. Paratuberculosis cases were diagnosed based on clinical symptoms, pathological autopsy, and histopathological inspection. Characteristics of paratuberculosis in the affected dairy cattle included poor body condition, persistent diarrhea, subcutaneous edema, granulomatous ileitis (multibacillary), mesenteric lymphadenitis, and hepatitis. Acid-fast bacilli from fecal specimens and lymphocytes were putatively identified as MAP based on Ziehl-Neelsen staining, then confirmed using polymerase chain reaction-based testing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses. Overall, only one MAP strain was isolated from a herd with symptomatic diarrhea. However, analysis of 586 serum samples from nine herds in Tai’an City revealed that 66.7% of herds and 14.2% of animals were seropositive for MAP. Our findings suggest that paratuberculosis is widely prevalent and therefore a significant threat to the dairy industry in Tai’an City, Shandong Province, China