491 research outputs found
Analysis of mechanical properties of transition segment of road and bridge based on high-strength foam concrete
The settlement difference in the transition section of road and bridge may lead to traffic accidents, which has many negative effects. Back filling of foam concrete behind abutment is a good method of treatment. In this study, a kind of high-strength foam concrete was designed for back filling of transition section of road and bridge, and the mechanical properties of the transition section of road and bridge were analyzed. It was found that only a large number of micro cracks grew in high-strength concrete under a large number of load cycles, and structural damage did not happen, indicating the high-strength foam concrete had high strength and long service life; the static base pressure was about 40 KPa, indicating a small burden on the structure. Under the vehicle load, the vertical displacement of the transition section of road and bridge with back filling of high-strength foam concrete behind abutment was about 0.7 m and the maximum vertical stress was about -40 KPa, which was significantly lower than that of the ordinary concrete, and the stability was favourable, indicating that the high-strength foam concrete had good vibration absorption effect. The analysis results verifies the value of the high-strength foam concrete as the backfill material of the transition section of road and bridge, providing some theoretical basis for its application and popularization
Basalt Fibers in Modified Whisker Reinforced Cementitious Composites
The calcium carbonate whisker (CW) and basalt fiber are gaining popularity due to its enhanced mechanical properties in composites. Also, the short and long fibers provide bridging role and resistance against cracking from micro- to macro-scale, respectively. The usage of long and short hybrid basalt fiber along with addition of CW in cement-based composites is still a research gap. In this work, experimental behavior of CW basalt hybrid fiber reinforced mortar is considered with various content and length (3 mm, 6 mm, 12 mm, and 20 mm) of hybrid basalt fibers. In addition to this, synergy performance index is determined to quantitatively evaluate the positive interaction of hybrid basalt fiber in cementitious materials. The strengthening effect of whiskers and basalt fibers are also studied using scanning electron microscopy. The CW with various basalt fiber contents having different length of hybrid basalt fiber is used. It was found that the four various length of hybrid basalt fiber together with CW in cement mortar exhibited enhanced compressive, flexural, and split tensile strength than that of pure mortar and single length basalt fiber reinforced cementitious mortar. The results of synergy performance index showed similar trend with the experimental results. The strengthening effect caused by step by step crack arresting mechanism was also observed in cementitious material
Algorithmic Fusion of Gene Expression Profiling for Diffuse Large B-Cell Lymphoma Outcome Prediction
Many different methods and techniques have been investigated for the processing and analysis of microarray gene expression profiling datasets. It is noted that the accuracy and reliability of the results are often dependent on the measurement approaches applied, and no single measurement so far is guaranteed to generate a satisfactory result. In this paper, an algorithmic fusion approach is presented for extracting genes that are predictive to clinical outcomes (survival-fatal) of diffuse large B-cell lymphoma on a set of microarray data for gene expression profiling. The approach integrates a set of measurements from different aspects in terms of the discrepancy indications and merit expectations of the gene expression patterns with respect to the clinical outcomes. A combination of statistical and nonstatistical criteria, continuous and discrete parameterizations, as well as model-based and modeless evaluations is applied in the approach. By integrating these measurements, a set of genes that are indicative to the clinical outcomes are better captured from the gene expression profiling dataset
Finite-time lag projective synchronization of delayed fractional-order quaternion-valued neural networks with parameter uncertainties
This paper discusses a class issue of finite-time lag projective synchronization (FTLPS) of delayed fractional-order quaternion-valued neural networks (FOQVNNs) with parameter uncertainties, which is solved by a non-decomposition method. Firstly, a new delayed FOQVNNs model with uncertain parameters is designed. Secondly, two types of feedback controller and adaptive controller without sign functions are designed in the quaternion domain. Based on the Lyapunov analysis method, the non-decomposition method is applied to replace the decomposition method that requires complex calculations, combined with some quaternion inequality techniques, to accurately estimate the settling time of FTLPS. Finally, the correctness of the obtained theoretical results is testified by a numerical simulation example
Conjugating drug candidates to polymeric chains does not necessarily enhance anti-influenza activity
Using the plaque reduction assay, relatively simple bicyclic quinone molecules, as well as multiple copies thereof covalently attached to a long polyglutamate-based polymeric chain, were examined as new inhibitors of various naturally occurring strains of influenza A virus. The polymer-conjugated inhibitors were found to have a far greater potency (for some as high as two orders of magnitude when a long spacer arm was employed) than their corresponding parent molecules against the human Wuhan influenza strain. However, such polymeric inhibitors failed to exhibit higher potency compared with their small molecule predecessors against the human Puerto Rico and avian turkey influenza strains. These observations, further explored by means of molecular modeling, reveal the previously unrecognized unpredictability of the benefits of multivalency, possibly because of poor accessibility of the viral targets to polymeric agentsNational Institutes of Health (U.S.) (Grant U01-AI074443
Fine Particulate Matter Constituents and Cardiopulmonary Mortality in a Heavily Polluted Chinese City
Background: Although ambient fine particulate matter (PM2.5; particulate matter ≤ 2.5 µm in aerodynamic diameter) has been linked to adverse human health effects, the chemical constituents that cause harm are unknown. To our knowledge, the health effects of PM2.5 constituents have not been reported for a developing country
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Gender Gaps in the Measurement of Public Opinion About Homosexuality in Cross-national Surveys: A Question-Wording Experiment
Measures of attitudes towards homosexuality in cross-national studies have received criticism for not being ‘gender-sensitive’. The current study used a split-ballot design allowing for separate analyses of the attitudes towards ‘gay men and lesbian women’, ‘gay men’, and ‘lesbian women’ in a pooled sample of 3,381 participants from Great Britain, Hungary, and Portugal. Analyses controlling for sociodemographics showed that differences in attitudes towards male and female targets were generally small and did not interact with the gender of the rater. In addition, results showed that men’s attitudes towards homosexuality were more strongly related to their gender ideology than women’s attitudes. Implications of these findings for cross-national studies measuring attitudes towards homosexuality are discussed
Screening of functional antidotes of RNA aptamers against bovine thrombin
AbstractA specific RNA aptamer (T705) against bovine thrombin had been obtained after seven rounds of SELEX (systematic evolution of ligands by exponential enrichment) selection from a random RNA library previously. In order to further investigate the relationship between the structure and function of this aptamer, three truncated RNA aptamers, T705a, T705b and T705c, were designed according to the secondary structure of T705 RNA. Our results showed that T705c keeping the precise stem–loop structure but lacking most of the stem region sequence of T705 could inhibit clot formation in vitro in the same way as its parental form. We also report here that single-stranded DNA (ssDNA) antisense oligonucleotides, c′ and c′-22, which were complementary to different portions of T705c could act as efficient antidotes reversing the inhibitory activity of T705. It is demonstrated for the first time that ssDNA antisense oligonucleotides are potential antidotes of RNA aptamers and this may be an effective, rapid strategy to find antidotes of RNA aptamers which would be of important usefulness in basic research and drug screening
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