MicroRNAs (miRNAs) are small regulatory RNAs that can regulate gene expression by binding to mRNA sequences and repressing target-gene expression post-transcriptionally, either by inhibiting ...translation or promoting RNA degradation. We have analysed expression of 328 known and 152 novel human miRNAs in 10 benign peripheral zone tissues and 16 prostate cancer tissues using microarrays and found widespread, but not universal, downregulation of miRNAs in clinically localized prostate cancer relative to benign peripheral zone tissue. These findings have been verified by real-time RT-PCR assays on select miRNAs, including miR-125b, miR-145 and let-7c. The downregulated miRNAs include several with proven target mRNAs whose proteins have been previously shown to be increased in prostate cancer by immunohistochemistry, including RAS, E2F3, BCL-2 and MCL-1. Using a bioinformatics approach, we have identified additional potential mRNA targets of one of the miRNAs, (miR-125b) that are upregulated in prostate cancer and confirmed increased expression of one of these targets, EIF4EBP1, in prostate cancer tissues. Our findings indicate that changes in miRNA expression may have an important role in the biology of human prostate cancer.
Functionally graded materials are regarded as a special kind of composites capable of eliminating material interfaces and the delamination problems. Stress discontinuity can be avoided owing to ...smooth composition of the functionally graded ingredients. In this study, a recently emerged effective non-local continuum theory for solving fracture problems in solids and structures, peridynamics, is employed to simulate dynamic wave propagation as well as crack propagation in functionally graded materials. Specifically, the ordinary state-based formulation is adopted. The ordinary state-based formulation is slightly modified for the modelling of functionally graded materials. The averaging technique is employed to determine peridynamic parameters associated with the material properties. Firstly, a benchmark problem is considered to validate the present implementation of ordinary state-based peridynamics for brittle fracture of homogeneous materials. Then, the wave propagation in the functionally graded materials under impact loading is simulated. Finally, dynamic crack propagation in the functionally graded materials is studied. The evaluated crack paths and the displacement waves are compared with reference works including numerical and experimental results. Good agreement between the reference and present results is achieved. It is shown that a simple modification of ordinary state-based formulation has led to simulate dynamic fracture of functionally graded materials.
The electronic transport properties of monolayer graphene are presented with an Ensemble Monte Carlo method where a rejection technique is used to account for the occupancy of the final states after ...scattering. Acoustic and optic phonon scatterings are considered for intrinsic graphene and in addition, ionized impurity and surface roughness scatterings are considered for the case of dirty graphene. The effect of screening is considered in the ionized impurity scattering of electrons. The time dependence of drift velocity of carriers is obtained where overshoot and undershoot effects are observed for certain values of applied field and material parameters for intrinsic graphene. The field dependence of drift velocity of carriers showed negative differential resistance and disappeared as acoustic scattering becomes dominant for intrinsic graphene. The variation of electron mobility with temperature is calculated for intrinsic (suspended) and dirty monolayer graphene sheets separately and they are compared. These are also compared with the mobility of two dimensional electrons at an AlGaN/GaN heterostructure. It is observed that interface roughness may become very effective in limiting the mobility of electrons in graphene.
Geometrically nonlinear analysis of flat, curved and folded shells under finite rotations is performed by enhanced six degrees of freedom (6-DOFs) meshfree formulation. Curvilinear surfaces are dealt ...with the concept of convected coordinates. Equilibrium equations are derived by total Lagrangian formulation with Green–Lagrange strain and Second Piola–Kirchhoff stress. Both shell geometry and its deformation are approximated by Reproducing Kernels (RKs). Transverse shear strains are considered by Mindlin–Reissner theory. Numerical integration of the stiffness matrix is estimated by using the Stabilized Conforming Nodal Integration (SCNI) method. To show accuracy and effectiveness of the proposed formulation and discretization, benchmark problems from the literatures are considered. Apart from reference solutions available in the literature, additional reference results based on finite element method (FEM) conducted by the present authors are also presented.
In 1956, Miller 1 conjectured that there is an upper limit on our capacity to process information on simultaneously interacting elements with reliable accuracy and with validity. This limit is seven ...plus or minus two elements. He noted that the number 7 occurs in many aspects of life, from the seven wonders of the world to the seven seas and seven deadly sins. We demonstrate in this paper that in making preference judgments on pairs of elements in a group, as we do in the analytic hierarchy process (AHP), the number of elements in the group should be no more than seven. The reason is founded in the consistency of information derived from relations among the elements. When the number of elements increases past seven, the resulting increase in inconsistency is too small for the mind to single out the element that causes the greatest inconsistency to scrutinize and correct its relation to the other elements, and the result is confusion to the mind from the existing information. The AHP as a theory of measurement has a basic way to obtain a measure of inconsistency for any such set of pairwise judgments. When the number of elements is seven or less the inconsistency measurement is relatively large with respect to the number of elements involved; when the number is more it is relatively small. The most inconsistent judgment is easily determined in the first case and the individual providing the judgments can change it in an effort to improve the overall inconsistency. In the second case, as the inconsistency measurement is relatively small, improving inconsistency requires only small perturbations and the judge would be hard put to determine what that change should be, and how such a small change could be justified for improving the validity of the outcome. The mind is sufficiently sensitive to improve large inconsistencies but not small ones. And the implication of this is that the number of elements in a set should be limited to seven plus or minus two.
Peridynamics has attractive features for solving several fracture mechanics problems. On the other hand, to ensure the accuracy, a large amount of particles (material points) is required. ...Introduction of variable horizon is an alternative approach by changing the horizon size over the problem domain. In the present study, we propose a novel variable horizon concept. It is known that an undesired “ghost” force arises along the transition region of different horizons. In order to suppress the ghost force, the gradual variation in the horizon size over a certain region, called smoothing length, is introduced between different scale particle distributions. Efficiency of the smoothed variable horizon peridynamics is demonstrated by several numerical studies employing the ordinary state-based peridynamics. As a basic case, a linear displacement field is considered. It is observed that the proposed approach significantly reduces the ghost forces along the interface of different spatial discretizations. Additionally, the dynamic stress intensity factors of stationary cracks are carefully examined. The path independence of the fracture parameters in the variable horizon peridynamics is ensured. The efficiency of the presented method is then discussed. It is monitored that introduction of the smoothing length concept significantly reduces the computational costs in the peridynamic modeling.
Schirmer and tear film break-up time tests are most commonly used in the diagnosis of dry eye syndrome. The aim of the study is to investigate the age- and gender-related changes in the results of ...Schirmer and tear film break-up time tests in normal population.
This randomized prospective study included 140 normal volunteers (70 male and 70 female subjects) with no ocular symptoms or ocular surface disorders. Schirmer and tear film break-up time tests were assessed in only one eye (right) of each subject. The study subjects were divided into seven groups according to their ages. Each group was composed of 20 eyes of 20 subjects (10 male and 10 female subjects). For variance analysis, Kruskal-Wallis test was used. Mann-Whitney U-test was performed for double comparisons.
We detected a statistically highly significant difference among the age groups in respect to the tear film break-up time test (P<0.001), especially there was a statistically highly significant difference between the younger and older age groups. There was no statistically significant difference in the Schirmer test results. But, we found that Schirmer test values were gradually decreased with advancing age. Tear function tests did not show statistically significant difference according to sex.
Our results reveal that there is a decline in the tear function test values, especially the tear film break-up time test values with advancing age. We suggest that the age of subjects should be taken into consideration in the evaluation of tear function test results.
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