This paper presents a new procedure to optimize the geometric parameters of a n-type coaxial HPGe detector. It is based on a statistical technique called “Design of Experiments” (DoE). This technique ...aims to identify the most influential parameters and to determine the optimal configuration. In this work, The effects of each parameter on the detector responses have been investigated by a fractional factorial design. Only the most influential factors contributing to the detector response have been selected. Precise modeling of these factors was then performed using a full factorial design. Based on the results obtained from this design, the full energy peak efficiencies according to the geometric parameters were modeled by a multiple-linear regression. These models have been statistically validated by analysis of variance (ANOVA). The optimal combination of the geometric parameters has been identified using the desirability function approach, which is a useful tool to optimize multi-response problems. A verification test was performed to validate the results obtained. It was observed that the relative deviation found between experimental and simulated values was less than 5%.
•Optimization of geometrical dimensions of an HPGe detector.•Application of Monte Carlo simulation and “Design of Experiments” technique.•Investigating influence of each detector parameter on the FEPE.•Achieving good agreement between the measured and the simulated results.
Personal and environmental radiation monitoring services are widely used through luminescent techniques. In this paper, we practiced performance testing on thermoluminescent and optically stimulated ...luminescent dosimeters by assessing their homogeneity, linearity, energy, and angular dependence tests. The IEC and ICRP requirements were used to compare the performance response of dosimeters. Based on the experimental results, we realized that both detectors comply with the international criteria. The homogeneity percentage was 8.9% and 13.7% for TL and OSL detectors, respectively. The percentage deviation of the linearity test does not exceed 10% for both dosimeters except for the TL dosimeters at low irradiation dose. For the angular dependence, deviations were less than 2% for TLDs and 5% for OSLDs. These detectors display mean values of the relative energy response of −15.29% and −6.51% for OSL and TL detectors. Generally, TL materials manifested low sensitivity to radiation dose levels. On the other hand, the OSLDs demonstrated a more pronounced under-response to energy beam qualities than TLDs. Regarding COV tests, TL and OSL dosimeters have passed the c2 test.
•TL and OSL dosimeters characteristics were tested.•Nine radiation qualities and eleven angles of incidence were used to test homogeneity, non-linearity, energy, and angular dependence.•The Hp(10) measurement accuracy was evaluated by both the ICRP trumpet curve analysis and IEC 62387 covariance test.
This work aims to establish some X-ray qualities recommended by the International Standard Organization (ISO) using the half-value layer (HVL) and Hp(10) dosimetry approaches. The HVL values of the ...following qualities N-60, N-80, N-100, N-150 and N-250 were determined using various attenuation layers. The obtained results were compared to those of reference X-ray beam qualities and a good agreement was found (difference less than 5% for all qualities). The GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations) radiation transport Monte Carlo toolkit was employed to simulate the production of X-ray spectra. The characteristics HVLs, mean energy and the spectral resolution of simulated spectra have been calculated and turned out to be conform to the ISO reference ones (difference less than the limit allowed by ISO). Furthermore, the conversion coefficients from air kerma to personal dose equivalent for simulated and measured spectra were fairly similar (the maximum difference less than 4.2%).
This work aims to establish some X-ray qualities recommended by the International Standard Organization (ISO) using the half-value layer (HVL) and Hp(10) dosimetry approaches. The HVL values of the ...following qualities N-60, N-80, N-100, N-150 and N-250 were determined using various attenuation layers. The obtained results were compared to those of reference X-ray beam qualities and a good agreement was found (difference less than 5% for all qualities). The GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations) radiation transport Monte Carlo toolkit was employed to simulate the production of X-ray spectra. The characteristics HVLs, mean energy and the spectral resolution of simulated spectra have been calculated and turned out to be conform to the ISO reference ones (difference less than the limit allowed by ISO). Furthermore, the conversion coefficients from air kerma to personal dose equivalent for simulated and measured spectra were fairly similar (the maximum difference less than 4.2%).
Background: Breast cancer is the most common cancer among women in most countries of the world. It is ranked first in females in Morocco (accounting for 33.4% of the total cancer burden) and more ...than 60% of cases are diagnosed at stage III or IV. During the last decade, health-related quality of life (HRQOL) has become an important aspect of breast cancer treatment. The objective of this study was to describe self-reported HRQOL in patients with breast cancer and to investigate its associations with sociodemographic and clinical variables. Methods: A prospective study was carried out in the main oncology centers in Morocco. Quality of life was measured using the Moroccan Arabic versions of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C 30 (EORTC QLQ C30) and the Breast Cancer-Specific Quality of Life Questionnaire (EORTC QLQ-BR23). Statistical analyses were performed using descriptive statistics and multivariate analyses. Results: A total of 1463 subjects were included in the study, with a mean age of 55.6 (SD. 11.2) years, 70% being married. The majority had stage II (45.9%) and a few cases stage IV (12.9%) lesions. The participants' global health mean score was 68.5 and in "functional scales", social functioning scored the highest (Mean 86.2 (SD=22.7)). The most distressing symptom on the symptom scale was financial difficulties (Mean 63.2 (SD=38.2)). Using the disease specific tool, it was found that future perspective scored the lowest (Mean 40.5 (SD=37.3)). On the symptom scale, arm symptoms scored the highest (Mean 23.6 (SD=21.6)). Significant mean differences were noted for many functional and symptom scales. Conclusion: Our results emphasized that the general HRQOL for our study population is lower than for corresponding populations in other countries. This study provided baseline information on the quality of life for a large sample of Moroccan women diagnosed with breast cancer.
Objective: The benefits of screening and early detection of breast cancer, including reduced morbidity and mortality, have been well-reported in the literature. In 2011, a breast cancer screening ...program was launched in Meknes-Tafilalt region of Morocco. The aim of this study was to evaluate the early performance indicators of this program. Materials and Methods: This retrospective evaluative study was conducted between April 2012 and December 2014, in Meknes-Tafilalt region of Morocco. Several performance indicators of the breast cancer screening program were calculated: the compliance rate, the positivity rate, the referral rate, the cancer detection rate and the organizational indicators. Results: During 2012-2014, a total of 184,951 women participated in the breast cancer screening program. The compliance rate was 26%, the positive rate was 3.3%, the referral rate was 36.7%, and the cancer detection rate was 1.2 per 1,000 women. The median time between the date of clinical breast examination and the date of biopsy (or cyto-puncture) was 36 days. The median time between the date of positive mammography and the date of biopsy (or cyto-puncture) was 6 days. The median time between the date of clinical breast examination and the date of the first received treatment was 61 days. Conclusions: The program needs better monitoring, as well as implementation of quality assurance tools to improve performance in our country.
Background: This study documented the performance of providers of visual inspection with acetic acid (VIA) at primary health centers, assessing their compliance with the VIA skills checklist and ...determinants of non-compliance, and exploring their perceptions of VIA training sessions. Materials and Methods: A cross-sectional study was conducted among VIA providers in the $Mekn\grave{e}s$-Tafilalet region of Morocco. Structured observation of their performance was conducted through supervisory visits and multiple focus group discussions (FGDs). Results: Performance of all the recommended steps for effective communication was observed in a low proportion of procedures (36.4%). Midwives/nurses had higher compliance than general practitioners (GPs) (p<0.001). All recommended steps for VIA examination were performed for a high proportion of procedures (82.5%). Compliance was higher among midwives/nurses than among GPs (p<0.001) and among providers in rural areas than those in urban areas (p<0.001). For pre-VIA counselling, all recommended steps were performed for only 36.8% of procedures. For post-VIA counseling, all recommended steps were performed in a high proportion (85.5% for VIA-negative and 85.1% for VIA-positive women). Midwives/nurses had higher compliance than GPs when advising VIA-positive women (p=0.009). All infection prevention practices were followed for only 14.2% of procedures, and compliance was higher among providers in rural areas than those in urban areas (p<0.001). Most FGD participants were satisfied with the content of VIA training sessions. However, they suggested periodic refresher training and supportive supervision. Conclusions: Quality assurance of a cervical cancer screening program is a key element to ensure that the providers perform VIA correctly and confidently.
Understanding high-temperature superconductivity is nowadays a challenge in the area of quantum materials and presents major unsolved problems. The recent discovery of superconductivity in ...infinite-layer nickelates has provided a new platform for studying unconventional superconductivity. Although the nickelates are analogous to the cuprates high-temperature superconductors, many theoretical analyses indicate that the nickelates do not precisely mirror the cuprates. For instance, hybridization between Ni 3dx2−y2 and O 2p is weak, which presents a high contrast to the hybridization between Cu 3d and O 2p in the cuprates. The similarities and differences between the nickelates and the cuprates provide great opportunities to reveal the origin of high-temperature superconductivity. In this study, with the employment of first-principles density-functional-theory calculations, we determine and analyze the electronic structure of the undoped infinite-layer nickelate NdNiO2. By performing phonon calculations and estimating the strength of the electron–phonon coupling, we find that this latter is weak, which indicates that the conventional BCS theory alone cannot explain the observed superconductivity in this material. Consequently, other still-unknown mechanisms may be at play. Moreover, we show from electronic band calculations that another conduction band crosses the Fermi level in addition to the Ni 3dx2−y2 band. This non-Ni conduction electron band is mainly composed of three orbitals: Nd 5d3z2−r2, Nd 5dxy, and another s-like orbital that does not belong to any specific atom. This interstitial s-like orbital is located around the (0,0,0.5) site. The rare-earth orbital Nd 5d3z2−r2 mixes with Ni 3dx2−y2 at the Fermi level, which causes some holes from the Nd 5d band to be (self-) doped into the Ni 3dx2−y2 orbitals.
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•DFT electronic structure of NdNiO2 is calculated.•Electron–phonon coupling in NdNiO2 is weak.•Ni 3dx2−y2, Nd 3d3z2−r2/3dxy contribute to the Fermi surface.•A new s-like orbital centered at (0,0,0.5) also contributes to the Fermi surface.
Background: In Morocco, the epidemiological profile of cervical cancer is not well established. The focus of the present study was both epidemiological and pathological characteristics. Methods: For ...all cases of cervical cancer treated between 2003 and 2007 in the National Institute of Oncology and the Oncology Department of the IbnRochd hospital (Casablanca), 900 cases were randomly selected. Results: The mean age was $52.1{\pm}11.8$ years. The most (90.5%) represented histological type was squamous cell carcinoma. For more than 57.0% cases the mean distance between patient's origin and center of treatment was greater than 100km. According to the FIGO classification, only 17.2% of patients were identified as being in early stages (0 and I). For 72.2% patients the follow-up did not exceed 2 years. At 1 year of following-up 55.8% of patients were alive and 43.4% were lost to following-up. Conclusion: Our study addressed the issue of the burden of cervical cancer in Morocco. The result provides a basis for decision-makers for the development of strategic measures to implement the fight against cervical cancer in Morocco.
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