Improving workflow for adaptive proton therapy with predictive anatomical modelling: A proof of concept

PURPOSE: To demonstrate predictive anatomical modelling for improving the clinical workflow of adaptive intensity-modulated proton therapy (IMPT) for head and neck cancer. METHODS: 10 radiotherapy patients with nasopharyngeal cancer were included in this retrospective study. Each patient had a planning CT, weekly verification CTs during radiotherapy and predicted weekly CTs from our anatomical model. Predicted CTs were used to create predicted adaptive plans in advance with the aim of maintaining clinically acceptable dosimetry. Adaption was triggered when the increase in mean dose (Dmean) to the parotid glands exceeded 3Gy(RBE). We compared the accumulated dose of two adaptive IMPT strategies: 1) Predicted plan adaption: One adaptive plan per patient was optimised on a predicted CT triggered by replan criteria. 2) Standard replan: One adaptive plan was created reactively in response to the triggering weekly CT. RESULTS: Statistical analysis demonstrates that the accumulated dose differences between two adaptive strategies are not significant (p>0.05) for CTVs and OARs. We observed no meaningful differences in D95 between the accumulated dose and the planned dose for the CTVs, with mean differences to the high-risk CTV of -1.20%, -1.23% and -1.25% for no adaption, standard and predicted plan adaption, respectively. The accumulated parotid Dmean using predicted plan adaption is within 3Gy(RBE) of the planned dose and 0.31Gy(RBE) lower than the standard replan approach on average. CONCLUSION: Prediction-based replanning could potentially enable adaptive therapy to be delivered without treatment gaps or sub-optimal fractions, as can occur during a standard replanning strategy, though the benefit of using predicted plan adaption over the standard replan was not shown to be statistically significant with respect to accumulated dose in this study. Nonetheless, a predictive replan approach can offer advantages in improving clinical workflow efficiency

Fabrication of Densely Packed AlN Nanowires by a Chemical Conversion of Al2O3Nanowires Based on Porous Anodic Alumina Film

Porous alumina film on aluminum with gel-like pore wall was prepared by a two-step anodization of aluminum, and the corresponding gel-like porous film was etched in diluted NaOH solution to produce alumina nanowires in the form of densely packed alignment. The resultant alumina nanowires were reacted with NH3and evaporated aluminum at an elevated temperature to be converted into densely packed aluminum nitride (AlN) nanowires. The AlN nanowires have a diameter of 15–20 nm larger than that of the alumina nanowires due to the supplement of the additional evaporated aluminum. The results suggest that it might be possible to prepare other aluminum compound nanowires through similar process

Investigating Saudi English language teachers' use and perceptions of the interactive whiteboard for teaching vocabulary in English as a foreign language in Saudi primary schools

Teaching vocabulary is a fundamental factor in English language teaching, as breadth of vocabulary is closely related to success in other areas of language learning such as reading, writing, speaking and listening. ICT has a potentially important role in teaching vocabulary within English as a foreign language, including through such media as the Interactive WhiteBoard (IWB), offering as it does a range of presentation formats that may facilitate the deeper and more effective processing of language. Despite this, relatively little is known about how teachers actually use the IWB, or indeed how they perceive it as a teaching tool. Understanding these issues is important in terms of informing the future development of the training offered to teachers in the use of the IWB. The current study includes the use of mixed methods, including a survey (319 responses). Six teachers participated in the qualitative part of the research, with four classroom observations of six teachers at three private and three state primary schools, followed by interviews with these same teachers. For the quantitative research, frequencies and descriptive statistics were computed to give an overview of teachers' reported use of the IWB and their attitudes towards it. Spearman Rank Order correlations and Mann-Whitney U-tests were employed in order to explore the relationships between key variables and whether different groups of respondents reported different perceptions and uses of the IWB. Teachers' perceptions and uses of the IWB were then further explored through a qualitative analysis of the interviews and classroom observations. Three complementary theoretical frameworks underpinned the study design and data analysis: Borg's (2003) work exploring language teachers' cognition and mental lives; the "Levels of Processing Hypothesis" (Craik & Lockhart, 1972) that outlines principles for vocabulary acquisition and retention; and Social-Cultural theory (Vygotsky, 1978), which guided the exploration of the classroom environment and how teachers scaffold learning from a low level to a high level through the IWB. The findings of this present study suggest a positive relationship between teachers' levels of skill/training in ICT and the frequency with which they make use of the IWB and the range of strategies for teaching vocabulary. The observations revealed that teachers who were trained in III ICT tended to use more varied teaching methods than those with less developed ICT skills. The interview analysis suggests that the majority of teachers believed that the use of the IWB in lessons assisted them in improving their students' new vocabulary retention. These findings make an important contribution to the field of educational technology for language learning by emphasising the link between training in ICT and the development of language teaching pedagogy

Superior gas sensing properties of beta-In2Se3 : A first-principles investigation

Using first-principles calculations, we report structural and electronic properties of CO, NO2 and NO molecular adsorption on beta-In2Se3 in comparison to a previous study on a-phase. Analysis and comparison of adsorption energies and extent of charge transfer indicates beta-In2Se3 to be selective in detecting gas molecules. We found NO molecules acting as charge donor whereas CO and NO2 molecules as charge acceptors, respectively, experiencing physisorption in all cases. Owing to enhanced adsorption, faster desorption and improved selectivity of the gas molecules discussed in detail, we conclude beta-In2Se3 to be a superior gas sensing material ideal for chemoresistive-type gas sensing applications

Thermoelectrics properties of two-dimensional materials with combination of linear and nonlinear band structures

We investigate thermoelectric (TE) properties of two-dimensional materials possessing two Dirac bands (a Dirac band) and a nonlinear band within the three-(two-)band model using linearized Boltzmann transport theory and relaxation time approximation. In the three-band model, we find that combinations of Dirac bands with a heavy nonlinear band, either a parabolic or a pudding-mold band, does not give much difference in their TE performance. The apparent difference only occurs in the position of the nonlinear band that leads to the maximum figure of merit ($ZT$). The optimum $ZT$ of the three-band model consisting of a nonlinear band is found when the nonlinear band intersects the Dirac bands near the Fermi level. By removing the linear conduction band, or, in other words, transforming the three-band model to the two-band model, we find better TE performance in the two-band model than in the three-band model, i.e., in terms of higher $ZT$ value

Copper Nanoparticles Decorated Alginate/Cobalt-Doped Cerium Oxide Composite Beads for Catalytic Reduction and Photodegradation of Organic Dyes

Cobalt-doped cerium oxide (Co–CeO2) was synthesized and wrapped inside alginate (Alg) hydrogel beads (Alg/Co–CeO2). Further, copper nanoparticles (Cu) were grown on Alg/Co–CeO2 beads. Cu decorated Alg/Co–CeO2 composite beads (Cu@Alg/Co–CeO2) were tested as a catalyst for the solar-assisted photodegradation and NaBH4-assisted reduction of organic pollutants. Among different dyes, Cu@Alg/Co–CeO2 was found to be the best catalyst for the photodegradation of acridine orange (ArO) under solar light and efficient in reducing methyl orange (MO) with the aid of NaBH4. Cu@Alg/Co–CeO2 decolorized ArO up to 75% in 5 h under solar light, while 97% of MO was reduced in 11 min. The decolorization efficiency of Cu@Alg/Co–CeO2 was further optimized by varying different parameters. Thus, the designed catalyst provides a promising way for efficient oxidation and reduction of pollutants from industrial effluents

Pre-treatment analysis of non-rigid variations can assist robust IMPT plan selection for head and neck patients

PURPOSE: To incorporate small non-rigid variations of head and neck patients into the robust evaluation of IMPT for the selection of robust treatment plans. METHODS: A cohort of 20 nasopharynx cancer patients with weekly kVCT and 15 oropharynx cancer patients with weekly cone beam CT (CBCT) were retrospectively included. Anatomical variations between week 0/week 1 of treatment were acquired using deformable image registration (DIR) for all 35 patients and then applied to the planning CT of four patients who have kVCT scanned each week to simulate potential small non-rigid variations (sNRVs). The robust evaluations were conducted on intensity-modulated proton therapy (IMPT) plans with: 1) different number of beam fields from 3-field to 5-field. 2) different beam angles. The robust evaluation before treatment including the sNRVs and setup uncertainty, referred to as sNRV+R evaluation was compared with the conventional evaluation (without sNRVs) in terms of robustness consistency with the gold standard evaluation based on weekly CT. RESULTS: Among four patients (490 scenarios), we observed a maximum difference in the sNRV+R evaluation to the nominal dose of: 9.37% dose degradation on D95 of CTVs, increase in mean dose (Dmean ) of parotid 11.87 Gy, increase in max dose (Dmax ) of brainstem 20.82 Gy. In contrast, in conventional evaluation, we observed a maximum difference to the nominal dose of: 7.58% dose degradation on D95 of the CTVs, increase in parotid Dmean by 4.88 Gy, increase in brainstem Dmax by 13.5 Gy. In the measurement of the robustness ranking consistency with the gold standard evaluation, the sNRV+R evaluation was better or equal to the conventional evaluation in 77% of cases, particularly, better on spinal cord, parotid glands and low-risk CTV. CONCLUSION: This study demonstrated the additional dose discrepancy that sNRVs can make. The inclusion of sNRVs can be beneficial to robust evaluation, providing information on clinical uncertainties additional to the conventional rigid isocenter shift. This article is protected by copyright. All rights reserved

Cross-Cultural Adaptation and Psychometric Properties of the Arabic Version of the Fall Risk Questionnaire

A simple, valid, and reliable self-assessment fall-risk questionnaire in Arabic is needed to significantly promote awareness and develop fall-prevention programs. This study translated and adapted the Fall Risk Questionnaire (FRQ) into Arabic and determined its validity and reliability among Saudi Arabian older adults in two phases: (1) cross-culturally adapting the FRQ into Arabic and (2) assessing the adapted questionnaire’s psychometric properties in two sessions with 110 Arabic-speaking participants aged ≥65 years. Pearson’s r showed that the Arabic FRQ had a significant moderate negative relationship with the Berg Balance Scale and fair-to-moderate positive correlations with Five Time Sit to Stand and Time Up and Go. The receiver operating characteristic curve indicated a significant area under the curve = 0.81. The cut-off score was 7.5 and associated with 73.7% sensitivity and 73.6% specificity. Internal consistency was estimated as good, with Cronbach’s α = 0.77. Deletion of item 1 slightly increased Cronbach’s α to 0.78. The Arabic FRQ demonstrated excellent test-retest reliability, with an intraclass correlation coefficient = 0.95 (95% CI: 0.92–0.97). It is highly valid and reliable in providing valuable data for evaluating fall risk in adults aged ≥65 years and for consulting a specialist for further investigation if necessary