Large Magnetoresistance in Compensated Semimetals TaAs2_2 and NbAs2_2

We report large magnetoresistance (MR) at low temperatures in single-crystalline nonmagnetic compounds TaAs$_2$ and NbAs$_2$. Both compounds exhibit parabolic-field-dependent MR larger than $5\times10^3$ in a magnetic field of 9 Tesla at 2 K. The MR starts to deviate from parabolic dependence above 10 T and intends to be saturated in 45 T for TaAs$_2$ at 4.2 K. The Hall resistance measurements and band structural calculations reveal their compensated semimetal characteristics. The large MR at low temperatures is ascribed to a resonance effect of the balanced electrons and holes with large mobilities. We also discuss the relation of the MR and samples' quality for TaAs$_2$ and other semimetals. We found that the magnitudes of MR are strongly dependent on the samples' quality for different compounds.Comment: 26 pages, 11 figures, 2 table

Large Magnetoresistance over an Extended Temperature Regime in Monophosphides of Tantalum and Niobium

We report extremely large magnetoresistance (MR) in an extended temperature regime from 1.5 K to 300 K in non-magnetic binary compounds TaP and NbP. TaP exhibits linear MR around $1.8\times 10^4$ at 2 K in a magnetic field of 9 Tesla, which further follows its linearity up to $1.4\times 10^5$ in a magnetic field of 56 Tesla at 1.5 K. At room temperature the MR for TaP and NbP follows a power law of the exponent about $1.5$ with the values larger than $300\%$ in a magnetic field of 9 Tesla. Such large MR in a wide temperature regime is not likely only due to a resonance of the electron-hole balance, but indicates a complicated mechanism underneath.Comment: 13 pages, 4 figures; submitted in May 20, 2015; accepted for publicatio

Cyclic Load Responses of GFRP-Strengthened Hollow Rectangular Bridge Piers

This study investigated the seismic behavior of glass fiber reinforced polymer (GFRP) strengthened hollow rectangular bridge piers. Cyclic testing of reinforced concrete (RC) piers retrofitted with GFRP was carried out under constant axial loading and lateral bending. The failure characteristics, flexural ductility, dissipated energy, and hysteretic behaviors, were analyzed based on experimental results. A simplified GFRP-confined concrete model is developed by considering effective strength coefficient and area distribution ratio of GFRP sheets. The results indicate that the failure modes and damage region would be changed and the ductility and dissipated energy of the GFRP-strengthened hollow rectangular bridge piers were improved greatly but not much improvement for the lateral load capacity. The analytical results of the force-displacement hysteretic loops based on the GFRP-confined concrete model developed in this paper agreed well with the experimental data

Experimental and numerical studies on multi-spherical sliding friction isolation bearing

An innovative multi-spherical sliding friction isolation (MSFI) bearing has recently been developed. The novel isolator has efficient energy dissipation capacity and enough displacement capacity under strong earthquake excitations. The MSFI bearing is completely passive devices, yet shows smart stiffness and smart damping under external excitation. The principles of operation and force-displacement relationship of the novel isolator are presented in this paper. The sliding order of all sliding surfaces and force-displacement hysteretic relationship are verified through a displacement-control testing program, and numerical analysis of the MSFI bearing under low cyclic loading is carried out based on ABAQUS program. The results show the sliding order and force-displacement relationship of the MSFI bearing derived from theoretical analysis results and numerical simulation results are well agree with experimental data which the compression-shear testing of the MSFI bearing specimen with the identical curvature radii and friction coefficients. The adaptive behavior of MSFI bearing permits the isolation system to be separately optimized for multiple levels of seismic intensity and ground motions

Hysteretic behavior simulation of novel rhombic mild steel dampers

Structural vibration control technique is an appropriate and acceptable method to control structural vibration condition and dissipate structural vibration energy during severe earthquakes and violent winds. Metallic dampers are verified to be stable and effective for passive control by many scholars and engineers. Low-yield-point (LYP) steel provides a promising prospect for energy dissipation dampers widely applied in structural engineering practice. Experimental study was conducted on a novel rhombic steel plate damper in former research and numerical simulation of the hysteretic behavior of rhombic dampers was performed in this study. Mechanical performance and implementation of the novel rhombic steel plate damper is briefly introduced in this paper. The hysteretic behavior of the novel rhombic steel plate dampers made of three types of steel was investigated by testing and finite element method. It is concluded that the yield strength enhancement of the rhombic steel damper made of LYP steel is substantial. The numerical simulation results of the hysteretic behavior of the rhombic steel plate damper are similar to the experimental results for these three types of steel. The energy dissipation capability of rhombic LYP steel dampers is excellent and adequate to be used in passive control strategy for civil engineering structures

A novel method to quantify local CpG methylation density by regional methylation elongation assay on microarray

<p>Abstract</p> <p>Background</p> <p>DNA methylation based techniques are important tools in both clinical diagnostics and therapeutics. But most of these methods only analyze a few CpG sites in a target region. Indeed, difference of site-specific methylation may also lead to a change of methylation density in many cases, and it has been found that the density of methylation is more important than methylation of single CpG site for gene silencing.</p> <p>Results</p> <p>We have developed a novel approach for quantitative analysis of CpG methylation density on the basis of microarray-based hybridization and incorporation of Cy5-dCTP into the Cy3 labeled target DNA by using Taq DNA Polymerase on microarray. The quantification is achieved by measuring Cy5/Cy3 signal ratio which is proportional to methylation density. This methylation-sensitive technique, termed RMEAM (regional methylation elongation assay on microarray), provides several advantages over existing methods used for methylation analysis. It can determine an exact methylation density of the given region, and has potential of high throughput. We demonstrate a use of this method in determining the methylation density of the promoter region of the tumor-related gene <it>MLH1, TERT </it>and <it>MGMT </it>in colorectal carcinoma patients.</p> <p>Conclusion</p> <p>This technique allows for quantitative analysis of regional methylation density, which is the representative of all allelic methylation patterns in the sample. The results show that this technique has the characteristics of simplicity, rapidness, specificity and high-throughput.</p

Pre- and post-diagnosis diabetes as a risk factor for all-cause and cancer-specific mortality in breast, prostate, and colorectal cancer survivors: a prospective cohort study

Objective: The relationship between diabetes and all- and cause-specific mortality in individuals with common cancers (breast, colorectal, and prostate) remains both under-researched and poorly understood.&nbsp;Methods: Cancer survivors (N = 37,993) from the National Health Interview Survey with linked data retrieved from the National Death Index served as our study participants. Cox proportional-hazards models were used to assess associations between pre- and post-diabetes and all-cause and cause-specific mortality.&nbsp;Results: Over a median follow-up period of 13 years, 2,350 all-cause, 698 cancer, and 506 CVD deaths occurred. Among all cancer survivors, patients with diabetes had greater risk of: all-cause mortality [hazard ratio (HR) 1.35, 95% CI = 1.27&ndash;1.43], cancer-specific mortality (HR: 1.14, 95% CI = 1.03&ndash;1.27), CVD mortality (HR: 1.36, 95% CI = 1.18&ndash;1.55), diabetes related mortality (HR: 17.18, 95% CI = 11.51&ndash;25.64), and kidney disease mortality (HR: 2.51, 95% CI = 1.65&ndash;3.82), compared with individuals without diabetes. The risk of all-cause mortality was also higher amongst those with diabetes and specific types of cancer: breast cancer (HR: 1.28, 95% CI = 1.12&ndash;1.48), prostate cancer (HR: 1.20, 95% CI = 1.03&ndash;1.39), and colorectal cancer (HR: 1.29, 95% CI = 1.10&ndash;1.50). Diabetes increased the risk of cancer-specific mortality among colorectal cancer survivors (HR: 1.36, 95% CI = 1.04&ndash;1.78) compared to those without diabetes. Diabetes was associated with higher risk of diabetes-related mortality when compared to non-diabetic breast (HR: 9.20, 95% CI = 3.60&ndash;23.53), prostate (HR: 18.36, 95% CI = 6.01&ndash;56.11), and colorectal cancer survivors (HR: 12.18, 95% CI = 4.17&ndash;35.58). Both pre- and post-diagnosis diabetes increased the risk of all-cause mortality among all cancer survivors. Cancer survivors with diabetes had similar risk of all-cause and CVD mortality during the second 5 years of diabetes and above 10 years of diabetes as compared to non-diabetic patients.&nbsp;Conclusions: Diabetes increased the risk of all-cause mortality among breast, prostate, and colorectal cancer survivors, not for pre- or post-diagnosis diabetes. Greater attention on diabetes management is warranted in cancer survivors with diabetes

Metallic surface states in a correlated d-electron topological Kondo insulator candidate FeSb2

The resistance of a conventional insulator diverges as temperature approaches zero. The peculiar low temperature resistivity saturation in the 4f Kondo insulator (KI) SmB6 has spurred proposals of a correlation-driven topological Kondo insulator (TKI) with exotic ground states. However, the scarcity of model TKI material families leaves difficulties in disentangling key ingredients from irrelevant details. Here we use angle-resolved photoemission spectroscopy (ARPES) to study FeSb2, a correlated d-electron KI candidate that also exhibits a low temperature resistivity saturation. On the (010) surface, we find a rich assemblage of metallic states with two-dimensional dispersion. Measurements of the bulk band structure reveal band renormalization, a large temperature-dependent band shift, and flat spectral features along certain high symmetry directions, providing spectroscopic evidence for strong correlations. Our observations suggest that exotic insulating states resembling those in SmB6 and YbB12 may also exist in systems with d instead of f electrons