Wide-angle monochromatic x-ray beam shutter: a design study

A novel design of a wide-angle monochromatic x-ray beam shutter is discussed. The shutter is designed as a compact unit capable of providing users with the means of shutting off the beam in secondary beamlines that are at an angle to the primary beamline and to each other. The single-unit design used the fact that all the secondary beamlines will be closed at the same time. The main challenge was to fit the shutter in the limited space of the existing Advanced Photon Source IMMW-CAT hutch. Space limitations led to the change in position of the actuator subassembly as compared to the standard shutter design. Although the actuator subassembly is placed underneath the shutter, fail-safe shutting is achieved by placing tungsten blocks above the beam while the shutter is open and using gravity to close the shutter in case of pneumatic failure. Redundancy required by safety concerns was achieved by duplicating the tungsten block/actuator subunits. Tungsten blocks of uneven length were used to counteract the increase in the center-to-center distance among secondary beamlines due to their angular offset. A special support table was designed to facilitate assembly and adjustability of the shutter position in the available space. To provide a radiation-tight hutch, a non-standard guillotine system was designed. In this paper, the design, specifications and optical ray tracing of the shutter assembly are presented

Micro Rna-21 Expression Levels in Invasive Breast Carcinoma with a Non-Invasive Component

Invasive ductal carcinomas with a non-invasive component (IDC-DCIS) are classified as a group of invasive breast carcinomas, together with pure invasive ductal carcinomas of the breast (IDC). MicroRNA-21 (miR-21) has been characterized as a factor of breast cancer invasiveness, however the difference in miR-21 expression levels between IDC-DCIS and pure IDC tumors and the correlations with standard diagnostic and prognostic parameters inside the IDC-DCIS group are unknown. Our aim was to determine if miR-21 had the ability to distinguish these two invasive breast cancer groups. Levels of miR-21 expression were measured by a stem-loop quantitative Real-Time PCR (RT-qPCR) method. Expression levels of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her-2) and proliferative index Ki-67 were evaluated by immunohistochemistry. IDC-DCIS tumors had significantly lower levels of miR-21 expression in grade 2 (P=0.003, Mann-Whitney U test), ER positive (P=0.025, Mann-Whitney U test) and PR positive tumors (P=0.024, Mann-Whitney U test) than pure IDCs. miR-21 levels showed a different pattern of expression in IDC-DCIS compared to IDC tumors, which is based on the difference in miR-21 expression between Her-2 negative and Her-2 positive IDC-DCIS tumors (P=0.030, Mann-Whitney U test) and high negative correlation of miR-21 levels with PR levels (rho=-0.886, P=0.006, Spearman correlation). According to our results, IDC-DCIS breast carcinomas act in a different manner in pure IDC tumors with regard to the relations between miR-21 expression levels and the standard diagnostic and prognostic parameters, such as Her-2 status, ER and PR status and protein levels

Thermomechanical analysis of high-heat-load components for the canted-undulator front end.

With the canted undulators operating at 200 mA at closed gap at the Advanced Photon Source in the future, the front end will receive 20.4 kW of total power and 281 kW/mrad{sup 2} of peak power density. Thermal analysis of the front-end high-heat-load components becomes an essential part of the front-end design. An extensive study has been conducted on the thermal design of the photon shutters and fixed masks. A unique dog-bone-shaped cross-section design for the photon shutters was derived to relieve high stress in the corners. The dual-undulator x-ray beams were simulated at several locations on the fixed mask to ensure the worst possible case is considered. Stress analysis on the fixed mask revealed that the maximum stress occurs when beam hits the intersection between the horizontal surface and the corner surface. The details of the analysis procedure are presented, and the failure criteria are discussed

Analysis of association of potentially functional genetic variants within genes encoding miR-34b/c, miR-378 and miR-143/145 with prostate cancer in Serbian population

MiRNA-associated genetic variants occurring in regulatory regions can affect the efficiency of transcription and potentially modify pri-miRNA or pre-miRNA processing. Since miRNA-based mechanisms are shown to be involved in the pathogenesis of prostate cancer (PCa), the aim of the present study was to evaluate the effect of rs4938723, rs1076064 and rs4705343 occurring in regulatory regions of miR-34b/c, miR-143/145 and miR-378, respectively, on PCa risk and progression in Serbian popul ation. We examined a total of 1060 subjects, of which 350 were patients with PCa, 354 were patients with benign prostatic hyperplasia (BPH), while 356 healthy volunteers were included in the control group. Genotyping of rs4938723, rs1076064 and rs4705343 was performed by using Taqman® SNP Genotyping Assays. Allele C of rs4705342 was found to increase the risk of PCa (P=0.031 for codominant model, P=0.0088 for recessive model). Rs1076064 minor allele G was found to associate with serum PSA score, as well as with PCa T category and disease aggressiveness. For rs4938723 minor allele C was shown to be associated with the lower PCa T category (Pdom=0.0046; OR=0.36, 95 % CI 0.17-0.76) in T2 vs. T1 comparison. Rs4705342 was identified as PCa susceptibility variant in Serbian population, while for rs1076064 and rs4938723 association with PCa progression parameters was found