Race-track microtron with pulse-to-pulse beam energy switch

A race-track microtron with a few beam orbits can be an alternative to a standard electron linear accelerator in a number of applications in which high beam power is not needed, like radiation therapy, industrial radiography or cargo inspection. In these cases the advantages of racetrack microtrons are low RF power consumption, and consequently low cost of the RF system, and a possibility of beam energy switch in a wide range by extracting the beam from different orbits. In the present work we describe the concept of a race-track microtron with pulseto- pulse beam energy switch in the range from 3.5 MeV to 9.5 MeV. Special attention is given to the optimization of the end magnets of a new type, which provide both the accelerating structure bypass and vertical beam focusingPostprint (published version

Comparing the Effects of Two Utility Value Interventions on Graduate Students\u27 Interest, Performance, and Perceptions of Utility Value

The present study compares the immediate and delayed effects of teacher- vs. student-generated utility value interventions on students\u27 interest, performance, and perceptions of utility value. In addition, it examines whether sense of autonomy mediates the relationship between type of utility value intervention and performance. The study is grounded in self-determination theory and expectancy-value theory and adopts a 3x3 mixed model design, with random assignment of participants to two relevance instruction conditions and a control condition. Findings suggest that the teacher-generated utility value intervention was more effective than the student-generated utility value intervention and the control condition in terms of increased performance and utility value. Furthermore, all students demonstrated significant increases on all dependent variables on the immediate post-test compared to the pre-test. The increased scores remained stable across time, with the exception of utility value, which dropped significantly from immediate to delayed post-test. Finally, the results indicate that autonomy did not mediate the effects of the utility value interventions on effort and performance. Educational implications and directions for future research are discussed

A New Approach for Accurate Identification of Allele State Based on Real-Time PCR for Biomedical Tasks

Genotyping of single nucleotide polymorphisms (SNPs) is an important task in medicine, veterinary medicine and biology. Precise differentiation of SNPs can be challenging. Methods based onTaqman can lead to false positive results due to nonspecific annealing of the probe. The aim of this research was to develop a new approach for the accurate differentiation of SNPs based on real-time PCR with Taqmanprobes and their rivals.The rivals competed with the Taqmanprobes for annealing to the site. The rivals blocked the nonspecific allele so that the Taqmanprobe could not anneal to it. Thus,the Taqmanprobe only detected specific alleles.This approach madeit possible to fine-tune the diagnostic system by selecting the ratio of Taqmanprobes and rivals (in non-equimolar amounts too).The new approach was tested on several diagonally significant SNPs in veterinary medicine.Using Taqman probes and rival probes showed a significantly greater specificity and efficiency in the determination of both homozygotes and heterozygotes than when conventional systems based only on Taqmanwere used. Keywords: SNP, allele identification, real-time PCR, fluorescent dy

Predictors of recall and reading time for seductive and nonseductive text segments

This correlational study explored how concreteness, relevance, importance, and interestingness related to the recall of seductive details and base text, while controlling for text coherence, and student background knowledge. Previous research has provided evidence for the significant relationship between these variables and the seductive details effect in particular and text recall in general. However, this is the first study to consider all these variables simultaneously. A group of 68 undergraduates read an expository text on lightning formation, performed an immediate test on free recall, and rated each text sentence for concreteness, relevance, importance, and interestingness. A simple regression analysis revealed that only interest significantly improved students\u27 recall of seductive sentences. However, none of the four ratings or the reading time predicted recall of base text sentences. Results regarding reading time demonstrated that seductive sentences were read faster than base text sentences. Strong positive correlation was revealed between relevance and importance. This result indicated that in the absence of explicit relevance instruction, relevance and importance could be used interchangeably. Significant positive correlation was revealed between concreteness and interest. However, this correlation was lower than expected. This result was interpreted in the light of Dual Coding Theory

Laparascopic-assisted endoscopic mucosal resection of a polyp in sigma and laparoscopic right hemicolectomy for adenocarcinoma in colon ascendens - case report

Today, endoscopic polypectomy has become a daily-performed routine procedure in the operating room. Almost every polyp in the colon can be removed endoscopically, but there are some problematic adenomas which are either large in size or difficult to approach. We present 80 years old white woman with a tubulo­villous adenoma with high-grade dysplasia on a flat surface located in sigma with 4 x 5cm in size and also synchronously found in colon ascendens a well differentiated G1 adenocarcinoma with 2 x 2cm in size on a flat surface. The abdominal ultrasound did not find any liver metastases. Because of the difficult location and the size of the two lesions in the right and left colon, we make a decision for a laparoscopic-assisted en­doscopic mucosal resection (piece-meal) of the polyp in sigma and for the adenocarcinoma in colon ascen­dens the procedure was followed by laparoscopic right hemicolectomy in one step approach. The both inter­ventions were performed without complications and good postoperative period. Hybrid endoscopic and lap­aroscopic interventions are very effective approach that can resect large tubulovillous polyps and adenocar­cinoma of the colon, with a lesser risk of complications. Combining the methods in one surgery save time, make endoscopy more easy to perform and can save one-half of the colon in cases of synchronous lesions of the colon. Scr Sci Med 2017; 49(3): 49-5

Rare-earth end magnets of a miniature race-track microtron and their tuning

We report basic results on the tuning of permanent end magnets of a compact 12 MeV race-track microtron (RTM) which is under construction at the Technical University of Catalonia. They are magnetic systems composed of four dipoles with the rare-earth permanent magnet (REPM) material used as a source of the magnetic field. The steel poles of the magnets are equipped with tuning plungers which allow to adjust the magnetic field level. In the article we shortly describe the tuning procedure and different techniques that were used in order to fulfill strict requirements of the field characteristics of the end magnets. It is shown that the obtained magnetic systems provide correct beam trajectories in the 12 MeV RTM. More detailed information about tuning procedure and results of tuning will be published elsewhere.Postprint (published version

Quadrupole lens and extraction magnets of a miniature race-track microtron

A compact 12 MeV race-track microtron (RTM) which is under construction at the Technical University of Catalonia includes a quadrupole magnet for horizontal beam focusing and four dipole magnets for beam extraction. As the source of the magnetic field in these magnets a rare-earth permanent magnet (REPM) material is used. In the article the main design characteristics of the quadrupole lens and extraction dipoles are described and a procedure of tuning of their magnetic fields is described. We report on the manufacturing of these magnetic systems and results of the tuning of their magnetic fields.Postprint (published version

2-year single center clinical experience in patients with colon cancer stage II and III receiving adjuvant chemotherapy

Introduction: Colorectal cancer is the most commonly diagnosed gastrointestinal cancer worldwide. For patients without metastatic disease, surgery is the first option used with curative intention, for stage I disease the adequate treatment consists only of surgical excision. In stage III additional adjuvant chemotherapy post-surgery is recommended. In stage II colon cancer, adjuvant treatment remains controversial.We aim to stratify patients according to different criteria, identify those with recurrence within the first year post last cycle of adjuvant chemotherapy and discuss those primary results.Materials and methods: a total of 52 patients who were subject to curative resection of stage II and III colon adenocarcinoma and who were administrated 5 FU based adjuvant chemotherapy were included and were followed for a period of two years. Data analysis was performed.Result: After a mean of 2 years of follow-up, recurrence was identified in 16 patients. None of stage II patients (n=6) and 3 patients in stage III (n=6) experienced recurrence. Patients with Nx cancer (n=30) were detached in separate group. Thirteen of them experienced recurrence (9 patients had relapse within 6 months after surgery - defined as synchronous metastatic disease).Conclusion: Surgery remains the cornerstone of treatment for the majority of colon patients. The selection of optimal chemotherapy for each patient is a complex process and there is a practice evidence gap which remains a significant problem. Our results for relapse are comparable with the reported ones worldwide. The reports suggest that there is still lack of evidence in the adjuvant colon cancer chemotherapy worldwide

Improving dental epithelial junction on dental implants with bioengineered peptides

Introduction: The functionalization of titanium (Ti) and titanium alloys (Ti6Al4V) implant surfaces via material-specific peptides influence host/biomaterial interaction. The impact of using peptides as molecular linkers between cells and implant material to improve keratinocyte adhesion is reported.Results: The metal binding peptides (MBP-1, MBP-2) SVSVGMKPSPRP and WDPPTLKRPVSP were selected via phage display and combined with laminin-5 or E-cadherin epithelial cell specific peptides (CSP-1, CSP-2) to engineer four metal-cell specific peptides (MCSPs). Single-cell force spectroscopy and cell adhesion experiments were performed to select the most promising candidate. In vivo tests using the dental implant for rats showed that the selected bi functional peptide not only enabled stable cell adhesion on the trans-gingival part of the dental implant but also arrested the unwanted apical migration of epithelial cells.Conclusion: The results demonstrated the outstanding performance of the bioengineered peptide in improving epithelial adhesion to Ti based implants and pointed towards promising new opportunities for applications in clinical practice