Search

The relationship between the maximum shear stress in a substrate solid and the elastic wave reflection coefficient from the interface between the substrate solid and an overlying solid half-space is investigated. Both substrate and overlying solid media are assumed to be initially isotropic and stress-free. Then as the substrate is subjected to horizontal confined stresses it becomes anisotropic. It is shown that longitudinal and shear wave reflection coefficients are related to the degree of stress induced anisotropy in the substrate medium. From this relation the confined stress level and the maximum shear stress generated on the vertical planes of the substrate are estimated. Authors in their previous investigation computed plane wave reflection coefficient in a biaxially compressed solid substrate immersed in a fluid. This paper reports for the first time how the maximum shear stress in a biaxially compressed substrate medium can be measured from the plane wave reflection coefficients when the overlying medium is also a solid half-space.

Chinese horseshoe crabs (Tachypleus tridentatus), ancient marine arthropods dating back to the mid-Palaeozoic Era, have provided valuable resources for the detection of bacterial or fungal contamination. However, excessive exploitation for the amoebocyte lysate of Tachypleus has dramatically decreased the population of the Chinese horseshoe crabs. Thus, we present sequencing, assembly and annotation of T. tridentatus, with the hope of understanding the genomic feature of the living fossil and assisting scientists with the protection of this endangered species. The final genome contained a total size of 1.943 Gb, covering 90.23% of the estimated genome size. The transcriptome of three larval stages was constructed to investigate the candidate gene involved in the larval development and validate annotation. The completeness of the genome and gene models was estimated by BUSCO, reaching 96.2% and 95.4%, respectively. The synonymous substitution distribution of paralogues revealed that T. tridentatus had undergone two rounds of whole-genome duplication. All genomic and transcriptome data have been deposited in public databases, ready to be used by researchers working on horseshoe crabs.

To investigate whether serum resistin correlated with hypertension, obesity, dyslipidemia, or insulin resistance (IR) in Chinese type 2 diabetes mellitus (T2DM) patients and their first-degree relatives (DFDRs) in a case–control observational study. We determined the serum levels of resistin, plasma lipids, glucose, and insulin, and performed clinical assessments of hypertension, obesity, and IR for 42 T2DM patients, 74 of their DFDRs, and 51 healthy control participants with no family history of T2DM (NC group). The biochemical and clinical variables were compared between the 3 groups, and relationships between serum resistin and the other variables were evaluated using a Pearson correlation analysis. Significant trends were observed in the triglyceride, HbA1c, and resistin levels, in which the values observed in the DFDR group were intermediate to those of the T2DM and NC groups (P

Aim The impact of viral status on recurrence of hepatitis B-related hepatocellular carcinoma (HCC) after curative therapy remains controversial. This meta-analysis aimed to determine whether the presence of viral load, genotype, specific mutation and antiviral therapy influenced HCC recurrence after curative therapy. Methods We performed a meta-analysis including 20 studies to assess the effect of viral status and antiviral therapy with nucleoside analog on recurrence of HCC after curative therapy. The pooled odds ratios (OR) were calculated using a random or fixed effects model. PUBMED, MEDLINE, EMBASE and the Cochrane Database were searched for articles published from 1990 to December 2012. Results Our results showed that the presence of high viral load significantly increased overall HCC recurrence risk after curative therapy. Pooled data from four studies on the recurrence rate among patients with genotype C infection compared with genotype B showed an increased risk of recurrence. Basal core promoter (BCP) mutation was associated with a significant risk in the recurrence of HCC. The pooled estimate of treatment effect was significantly in favor of a preventive effectiveness of antiviral therapy. Conclusion The present study suggested that HCC patients with high viral load, genotype C and BCP mutation had a significantly higher risk of recurrence. Antiviral therapy has potential beneficial effects after the curative treatment of HCC in terms of tumor recurrence.

Background Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus (SFTSV) with an average fatality rate of 12%. The clinical factors for death in SFTS patients remain unclear. Methods Clinical features and laboratory parameters were dynamically collected for 11 fatal and 48 non-fatal SFTS cases. Univariate logistic regression was used to evaluate the risk factors associated with death. Results Dynamic tracking of laboratory parameters revealed that during the initial fever stage, the viral load was comparable for the patients who survived as well as the ones that died. Then in the second stage when multi-organ dysfunction occurred, from 7-13 days after disease onset, the viral load decreased in survivors but it remained high in the patients that died. The key risk factors that contributed to patient death were elevated serum aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and creatine kinase fraction, as well as the appearance of CNS (central nervous system) symptoms, hemorrhagic manifestation, disseminated intravascular coagulation, and multi-organ failure. All clinical markers reverted to normal in the convalescent stage for SFTS patients who survived. Conclusions We identified a period of 7-13 days after the onset of illness as the critical stage in SFTS progression. A sustained serum viral load may indicate that disease conditions will worsen and lead to death.

The two principal functions of a primary cement job are to provide support for the casing and to provide hydraulic isolation between zones. A poor cement job may cause many issues during the well production. Therefore, cement bond evaluation is very important in well completion. The Sector Bond log (SBL) has been widely used for cement bond evaluation for years. The SBL tool has eight pairs of directional transmitter-receivers, which are equally distributed in azimuth and used for identifying channels and channel azimuths. To better understand SBL, using a parallel 3D finite difference algorithm, we numerically simulated acoustic responses of the SBL under a variety of cement bond scenarios and investigated the sensitivity of the integral amplitudes to channel size and its azimuth. We further developed a new approach to image potential channels in cement annulus using the integral amplitudes. The comparisons between conventional SBL images and the reprocessed ones using the new approach showed significant improvement on both synthetic and field data.

The velocities of shear waves propagating along radial direction of birch and elmwood specimens are measured in order to study the effect of anisotropy on shear wave velocity. The relationship between the shear wave velocity and the oscillation direction is examined by rotating an ultrasonic sensor. The results indicate that the effect of anisotropy on shear wave velocity in birch and elmwood specimens is similar to Japanese magnolia specimen. When the oscillation direction of the shear wave corresponds to the certain anisotropic direction of the wood specimen, the shear wave velocity decreases sharply and the relationship between shear wave velocity and rotation angle tends to become discontinuous. The intrinsic birefringence due to the anisotropy of birch and elmwood woods is observed. Their texture anisotropies are strong. In an isotropic nylon, on the contrary, the value of shear wave velocity was similar to a circular ring. This investigation is significant meanings in architectural and civil engineering field.

Detecting and characterizing the community structure of complex network is fundamental. We compare the classical optimization indexes of modularity and modularity density, which are quality indexes for a partition of a network into communities. Based on this, we propose a quantitative function for community partition, named communitarity or C value. We demonstrate that the quantitative is superior to modularity Q and modularity density D. Both theoretical and numerical results show that optimizing the new index not only can resolve small modules, but also can correctly identify the number of communities.

This paper has conducted a structural analysis by workbench after establishing a stable platform for automotive three-dimensional model, primarily concerning whether the platform can provide a benchmark to meet the requirements of equipment, including the numerical analysis of whether the platform tilt angle under load can achieve the requirements as well as the scheme of improvement direction of the structure.