Assessment of an Unshielded Electron Field Diode Dosimeter for Beam Scanning in Small-to Medium-Sized 6 MV Photon Fields

Abstract Introduction Radiotherapy planning systems require many percentage depth dose (PDD) and profile measurements and there are various dosimeters that can be used to obtain these scans. As dose perturbation is particularly troublesome in smaller photon fields, using a low-perturbation, unshielded electron field diode (EFD) in these fields is of interest. The aim of this work was to investigate the suitability of an unshielded diode for beam scanning in 3×3 cm 2 , 5×5 cm 2 , and 10×10 cm 2 , 6 MV fields. Materials and Methods An EFD was used for all the scans. For comparison, in profile measurements, a tungsten-shielded photon field diode (PFD) was also used. PDDs were measured using the PFD and an RK ionization chamber. Results Very good agreement (0.4%) was found between the PDDs measured with EFD and PFD for the two larger fields. However, the difference between them exceeded 1.0% slightly for the smallest field, which may be attributed to the effect of the larger PFD perturbation. The RK chamber PDDs around 10 cm depth were 1-2% lower than those measured with the diodes. There was good agreement (<1 mm) between EFD-and PFD-measured penumbra widths. Conclusion The EFD generally agrees well with the PFD and may even perform better in smaller fields

Developing a fuzzy ANP model for performance appraisal based on firm strategy

The purpose of this study is to develop a fuzzy Analytic Network Process (ANP) model that has the ability to evaluate employee performance in different strategies. A team of experts in the field of strategic human resource management and senior management of an organization engaged in steel production were involved in the study. The data collection tool was a questionnaire that was designed based on the criteria of organization's performance appraisal system. The results showed that in cost leadership strategy, compliance of work hierarchy, quantity of work and the ability to make important decisions constituted the highest coefficients, while in the focus strategy, participate in group work, power of supervision and administration and decision making ability had the highest importance. In differentiation strategy, innovation and creativity, quality and offering constructive suggestions received higher ratings than other criteria. Finally, the developed model was used to evaluate the performance of a sample employe

Comparative diagnosis of the alveolar antral artery canal in the lateral maxillary sinus wall in corresponding panoramic radiography and cone-beam computed tomography

Abstract Purpose Sinus lift operations are a tried and tested means of providing adequate implant prosthetics to patients with compromised jawbones. Knowledge of the arterial supply of the maxillary sinus region is essential for surgical treatment in this area. The aim of the present comparative study was to determine whether alveolar antral artery (AAA) canal can be diagnosed both in corresponding panoramic radiography (PR) and cone-beam computed tomography (CBCT). Methods A total of 335 patients with 635 sites and corresponding maxillary sinus in both PR and CBCT were selected and examined for AAA canal visibility. Results The visibility of the AAA canal was significantly higher in CBCT than in PR. A total of 154 (46.0%) AAA canals could be identified in the maxillary sinus on the right. However, only four (1.2%) of these were also visible in PR. The detected values of the AAA canals in the maxillary sinus on the left in the PR and CBCT images were similar to those of the right. While 164 AAA canals (49%) were observed in CBCT images, only 1 (0.3%) was identifiable in PR. Conclusions The results show that CBCT can be recommended for visualising the AAA canal when surgically planning sinus augmentation procedures. Graphical Abstrac

Electrospun Poly Caprolactone-Carbon Nanotube Scaffold for Nerve Regeneration in Dental Tissue Engineering

Regeneration and engineering of functional new tissues containing the neural network have great importance. Progression of neural network into the dental tissue has a crucial role in dental tissue regeneration. In the present study polymer-ceramic blended scaffolds containing different weight percentages of carbon nanotube in poly caprolactone nanofiber matrix were fabricated. Morphological, mechanical and electrical properties of the prepared scaffolds have been characterized. Results showed that the sample containing 5 weight % of carbon nanotube had the smallest mean fiber diameter (50 - 300 nm) and the highest mechanical behavior. Also, its electrical conductivity was suitable to be used in nerve tissue scaffolds. The static culture of the Schwann cells on the prepared scaffolds indicated that increasing weight percentage of carbon nanotube into the polycaprolactone matrix up to the 5 wt. % enhanced cell viability

Low volume polyethylene glycol combined with senna versus high volume polyethylene glycol, which regimen is better for bowel preparation for colonoscopy? A randomized, controlled, and single‐blinded trial

Abstract Background and Aims Bowel preparation affects the quality of colonoscopy. Reaching the optimal preparation has been a challenge for years. Polyethylene glycol (PEG) is the sole FDA‐approved substance for this purpose. However, patients find it unpleasant and often complain about its adverse effects. In this study, we aimed to reduce these complaints by lowering the amount of PEG and adding senna which is an herbal stimulant laxative. Methods Four hundred and eighty‐six patients were admitted for colonoscopy. Finally, 382 patients were enrolled in the study and we divided them into two groups; 186 patients were placed in which conventional high volume PEG‐alone regimen was consumed and 196 patients in which low volume PEG plus senna regimen was offered. The quality of colon preparation was compared between the two groups by independent two samples t‐test (or its corresponding nonparametric test), Fisher's exact, or χ2 test in SPSS software version 22. Results The colon preparation quality was equally efficient in the two groups as 69.36% in the high volume PEG group and 71.94% in PEG plus senna group had adequate bowel preparation (p = 0.58). Adverse effects, like nausea, bloating, headache, and sleeplessness were significantly less in the low volume PEG plus senna group. Conclusion Besides the fact that bowel preparation by low volume PEG plus senna combination was noninferior to the conventional high volume PEG‐alone regimen, the side effects were much less common with the low volume PEG plus senna regimen

The association between screen use and central obesity among children and adolescents: a systematic review and meta-analysis

Abstract Currently, there is no summative study evaluating the association between central obesity and screen time. This systematic review and meta-analysis aimed to summarize the results of studies evaluating the association between screen time and central obesity among children and adolescents. To this end, we performed a systematic search in three electronic databases, including Scopus, PubMed, and Embase to retrieve the related studies up to March 2021. Nine studies were eligible to be included in the meta-analysis. There was no association between odds of central obesity and screen time [odds ratio (OR) 1.136; 95% CI 0.965–1.337; P = 0.125]; however, waist circumference (WC) was 1.23 cm higher in those with highest screen time versus those in the lowest screen time category [weighted mean difference (WMD) = 1.23; 95% 95% CI 0.342–2.112; P = 0.007; Fig. 3]. Moreover, the possible sources of heterogeneity in the included studies were continent and sample size. No evidence of publication bias was reported. For the first time, the current systematic review and meta-analysis revealed that those with the highest screen time had higher WC compared with those with the lowest screen time. Although, there was no association between odds of central obesity and screen time. Due to the observational design of the included studies, it is impossible to infer the cause-effect relationship. Therefore, further interventional and longitudinal studies are warranted to better elucidate the causality of these associations