Objective: The aim of this study was to establish cervical cancer patients’ expectations and experiences during high dose-rate (HDR) intracavitary brachytherapy procedure, as part of a process to develop guidelines f...Objective: The aim of this study was to establish cervical cancer patients’ expectations and experiences during high dose-rate (HDR) intracavitary brachytherapy procedure, as part of a process to develop guidelines for quality patient-centered care. Methodology: A prospective, qualitative study with a descriptive phenomenological approach was used. Purposive sampling was carried out to recruit 31 women undergoing HDR brachytherapy for cervical cancer from June to August 2020 at the National Institute of Oncology in Rabat. Semi-structured, one-to-one interviews guided by a theme list were conducted by a female radiation oncologist in Arabic before, during and after treatment. The following aspects were discussed: expectations, experiences in the waiting room, in the treatment room, and suggestions for improvement. Data was transcribed, translated and thematic analysis performed. Results: Most of the patients felt unprepared and did not have a clear understanding of brachytherapy. Brachytherapy was a difficult experience causing fear and anxiety throughout treatment. Most women dreaded the procedure, before receiving the first treatment and even after having had one. Pain was a major problem for the participants. Some women compared this pain to childbirth, a process they preferred to brachytherapy. Patients agreed that the preventative medication received was not efficient to relieve the pain. Despite these negative experiences, patients were left with a positive outlook. Dialogue with the healthcare professionals, support from their family and fellow patients, envisaged outcomes and desires to heal were used to cope, whilst faith and spirituality gave them strength to endure the procedure. Conclusion: Women undergoing uterovaginal brachytherapy for cervical cancer experience pain and emotional distress. Providing patients with adequate information, more sensitive support during the procedure and debriefing afterwards could lessen feelings of fear and anxiety. Our findings advocate for the revision of pain manag展开更多
The enhanced low-dose-rate sensitivity （ELDRS） and dose-rate dependence of vertical NPN transistors are investigated in this article. The results show that the vertical NPN transistors exhibit more degradation at lo...The enhanced low-dose-rate sensitivity （ELDRS） and dose-rate dependence of vertical NPN transistors are investigated in this article. The results show that the vertical NPN transistors exhibit more degradation at low dose rate, and that this degradation is attributed to the increase on base current. The oxide trapped positive charge near the SiO2-Si interface and interface traps at the interface can contribute to the increase on base current and the two-stage hydrogen mechanism associated with space charge effect can well explain the experimental results.展开更多
Optically stimulated luminescence （OSL） is the luminescence emitted from a semiconductor during its exposure to light. The OSL intensity is a function of the total dose absorbed by the sample. The dose-rate dependen...Optically stimulated luminescence （OSL） is the luminescence emitted from a semiconductor during its exposure to light. The OSL intensity is a function of the total dose absorbed by the sample. The dose-rate dependence of the OSL signal of the semiconductor CaS doped Ce and Sm was studied by numerical simulation and experiments. Based on a one-trap/one-center model, the whole OSL process was represented by a series of differential equations. The dose-rate properties of the materials were acquired theoretically by solving the equations. Good coherence was achieved between numerical simulation and experiments, both of which showed that the OSL signal was independent of dose rate. This result validates that when using OSL as a dosimetry technique, the dose-rate effect can be neglected.展开更多
This paper presents the total ionizing dose test results at different biases and dose rates for AD9233, which is fabricated using a modern CMOS process. The experimental results show that the digital parts are more se...This paper presents the total ionizing dose test results at different biases and dose rates for AD9233, which is fabricated using a modern CMOS process. The experimental results show that the digital parts are more sensitive than the other parts. Power down is the worst-case bias, and this phenomenon is first found in the total ionizing dose effect of analog-to-digital converters. We also find that the AC as well as DC parameters are sensitive to the total ionizing dose at a high dose rate, whereas none of the parameters are sensitive at a low dose rate. The test facilities, results and analysis are presented in detail.展开更多
AIM: To investigate activity, toxicity, and prognostic factors for survival of erlotinib and fixed dose-rate gemcitabine (FDR-Gem) in advanced pancreatic cancer.METHODS: We designed a single-arm prospective, multicent...AIM: To investigate activity, toxicity, and prognostic factors for survival of erlotinib and fixed dose-rate gemcitabine (FDR-Gem) in advanced pancreatic cancer.METHODS: We designed a single-arm prospective, multicentre, open-label phase II study to evaluate the combination of erlotinib (100 mg/d, orally) and weekly FDR-Gem (1000 mg/m2, infused at 10 mg/m2 per minute) in a population of previously untreated patients with locally advanced, inoperable, or metastatic pancreatic cancer. Primary endpoint was the rate of progression-free survival at 6 mo (PFS-6); secondary endpoints were overall response rate (ORR), response duration, tolerability, overall survival (OS), and clinical benefit. Treatment was not considered to be of further interest if the PFS-6 was < 20% (p0 = 20%), while a PFS-6 > 40% would be of considerable interest (p1 = 40%); with a 5% rejection error (α = 5%) and a power of 80%, 35 fully evaluable patients with metastatic disease were required to be enrolled in order to complete the study. Analysis of prognostic factors for survival was also carried out.RESULTS: From May 2007 to September 2009, 46 patients were enrolled (male/female: 25/21; median age: 64 years; median baseline carbohydrate antigen 19-9 (CA 19-9): 897 U/mL; locally advanced/metastatic disease: 5/41). PFS-6 and median PFS were 30.4% and 14 wk (95%CI: 10-19), respectively; 1-year and median OS were 20.2% and 26 wk (95%CI: 8-43). Five patients achieved an objective response (ORR: 10.9%, 95%CI: 1.9-19.9); disease control rate was 56.5% (95%CI: 42.2-70.8); clinical benefit rate was 43.5% (95%CI: 29.1-57.8). CA 19-9 serum levels were decreased by > 25% as compared to baseline in 14/23 evaluable patients (63.6%). Treatment was well-tolerated, with skin rash being the most powerful predictor of both longer PFS (P < 0.0001) and OS (P = 0.01) at multivariate analysis (median OS for patients with or without rash: 42 wk vs 15 wk, respectively, Log-rank P = 0.03). Additional predictors of better outcome were: CA 19-9 reduction, female sex (for展开更多
The paper presents the key milestones and outcomes of 65-year studies of the carcinogenic consequences of accidental radiation exposure of the population of the Ural region.The radioactive contamination of the Techa R...The paper presents the key milestones and outcomes of 65-year studies of the carcinogenic consequences of accidental radiation exposure of the population of the Ural region.The radioactive contamination of the Techa River and the 1957 accident at the Mayak Production Association were the reasons of the long-term population exposure at a wide dose-range.The most important tasks of the study were the reconstruction of individual doses,follow-up of the solid cancer and leukemia incidence and mortality among cohort members.The research results have shown that chronic human exposure,in comparison to acute exposure,does not reduce the risk of developing malignant tumors and leukemias.The value of the dose-rate factor does not exceed"one".Thus,according to our data,the Publication 103 of the International Commission on Radiological Protection seemed to underestimate the radiation risk of malignant tumors and leukemias in case of low dose-rate exposure of the population by a factor of two.Prospects for further radio-epidemiological studies in the Urals are associated with the analysis of the cohort of Southern Urals Populations Exposed to Radiation,which includes about 63 thousand exposed people and makes it possible to assess the radiation risk of solid cancers of certain localizations,certain types of leukemia,and non-cancer effects.展开更多
Objective: To investigate the change of ATM phosphorylation in HepG2 cells and its effect on HepG2 cell survival under a continuous low dose-rate irradiation. Methods: HepG2 cells were exposed to equivalent doses of i...Objective: To investigate the change of ATM phosphorylation in HepG2 cells and its effect on HepG2 cell survival under a continuous low dose-rate irradiation. Methods: HepG2 cells were exposed to equivalent doses of irradiation deliv- ered at either a continuous low dose-rate (7.76 cGy/h) or a high dose-rate (4500 cGy/h). The ATM phosphorylated proteins and surviving fraction of HepG2 cell after low dose-rate irradiation were compared with that after equivalent doses of high dose-rate irradiation. Results: The phosphorylation of ATM protein was maximal at 0.5 Gy irradiation delivered at either a high dose-rate or a continuous low dose-rate. As the radiation dose increased, the phosphorylation of ATM protein decreased under continuous low dose-rate irradiation. However, the phosphorylation of ATM protein was remained stable under high dose-rate irradiation. When the phosphorylation of ATM protein under continuous low dose-rate irradiation was equal to that under high dose-rate irradiation, there was no significant difference in the surviving fraction of HepG2 cells between two ir- radiation methods (P > 0.05). When the phosphorylation of ATM protein significantly decreased after continuous low dose-rate irradiation compared with that after high dose-rate irradiation, increased amounts of cell killing was found in low dose-rate irradiation (P < 0.01). Conclusion: Continuous low dose-rate irradiation increases HepG2 cells radiosensitivity compared with high dose-rate irradiation. The increased amounts of cell killing following continuous low dose-rate exposures are associated with reduced ATM phosphorylated protein.展开更多
文摘Objective: The aim of this study was to establish cervical cancer patients’ expectations and experiences during high dose-rate (HDR) intracavitary brachytherapy procedure, as part of a process to develop guidelines for quality patient-centered care. Methodology: A prospective, qualitative study with a descriptive phenomenological approach was used. Purposive sampling was carried out to recruit 31 women undergoing HDR brachytherapy for cervical cancer from June to August 2020 at the National Institute of Oncology in Rabat. Semi-structured, one-to-one interviews guided by a theme list were conducted by a female radiation oncologist in Arabic before, during and after treatment. The following aspects were discussed: expectations, experiences in the waiting room, in the treatment room, and suggestions for improvement. Data was transcribed, translated and thematic analysis performed. Results: Most of the patients felt unprepared and did not have a clear understanding of brachytherapy. Brachytherapy was a difficult experience causing fear and anxiety throughout treatment. Most women dreaded the procedure, before receiving the first treatment and even after having had one. Pain was a major problem for the participants. Some women compared this pain to childbirth, a process they preferred to brachytherapy. Patients agreed that the preventative medication received was not efficient to relieve the pain. Despite these negative experiences, patients were left with a positive outlook. Dialogue with the healthcare professionals, support from their family and fellow patients, envisaged outcomes and desires to heal were used to cope, whilst faith and spirituality gave them strength to endure the procedure. Conclusion: Women undergoing uterovaginal brachytherapy for cervical cancer experience pain and emotional distress. Providing patients with adequate information, more sensitive support during the procedure and debriefing afterwards could lessen feelings of fear and anxiety. Our findings advocate for the revision of pain manag
文摘The enhanced low-dose-rate sensitivity （ELDRS） and dose-rate dependence of vertical NPN transistors are investigated in this article. The results show that the vertical NPN transistors exhibit more degradation at low dose rate, and that this degradation is attributed to the increase on base current. The oxide trapped positive charge near the SiO2-Si interface and interface traps at the interface can contribute to the increase on base current and the two-stage hydrogen mechanism associated with space charge effect can well explain the experimental results.
基金Project supported by the National Natural Science Foundation of China(Nos.10875168,10475112)
文摘Optically stimulated luminescence （OSL） is the luminescence emitted from a semiconductor during its exposure to light. The OSL intensity is a function of the total dose absorbed by the sample. The dose-rate dependence of the OSL signal of the semiconductor CaS doped Ce and Sm was studied by numerical simulation and experiments. Based on a one-trap/one-center model, the whole OSL process was represented by a series of differential equations. The dose-rate properties of the materials were acquired theoretically by solving the equations. Good coherence was achieved between numerical simulation and experiments, both of which showed that the OSL signal was independent of dose rate. This result validates that when using OSL as a dosimetry technique, the dose-rate effect can be neglected.
基金supported by the National Natural Science Foundation of China(No.11005152)
文摘This paper presents the total ionizing dose test results at different biases and dose rates for AD9233, which is fabricated using a modern CMOS process. The experimental results show that the digital parts are more sensitive than the other parts. Power down is the worst-case bias, and this phenomenon is first found in the total ionizing dose effect of analog-to-digital converters. We also find that the AC as well as DC parameters are sensitive to the total ionizing dose at a high dose rate, whereas none of the parameters are sensitive at a low dose rate. The test facilities, results and analysis are presented in detail.
基金Supported by A Grant of the National Ministry of Health and the Italian Association for Cancer Research (AIRC)An AIRC fellowship to Vaccaro V
文摘AIM: To investigate activity, toxicity, and prognostic factors for survival of erlotinib and fixed dose-rate gemcitabine (FDR-Gem) in advanced pancreatic cancer.METHODS: We designed a single-arm prospective, multicentre, open-label phase II study to evaluate the combination of erlotinib (100 mg/d, orally) and weekly FDR-Gem (1000 mg/m2, infused at 10 mg/m2 per minute) in a population of previously untreated patients with locally advanced, inoperable, or metastatic pancreatic cancer. Primary endpoint was the rate of progression-free survival at 6 mo (PFS-6); secondary endpoints were overall response rate (ORR), response duration, tolerability, overall survival (OS), and clinical benefit. Treatment was not considered to be of further interest if the PFS-6 was < 20% (p0 = 20%), while a PFS-6 > 40% would be of considerable interest (p1 = 40%); with a 5% rejection error (α = 5%) and a power of 80%, 35 fully evaluable patients with metastatic disease were required to be enrolled in order to complete the study. Analysis of prognostic factors for survival was also carried out.RESULTS: From May 2007 to September 2009, 46 patients were enrolled (male/female: 25/21; median age: 64 years; median baseline carbohydrate antigen 19-9 (CA 19-9): 897 U/mL; locally advanced/metastatic disease: 5/41). PFS-6 and median PFS were 30.4% and 14 wk (95%CI: 10-19), respectively; 1-year and median OS were 20.2% and 26 wk (95%CI: 8-43). Five patients achieved an objective response (ORR: 10.9%, 95%CI: 1.9-19.9); disease control rate was 56.5% (95%CI: 42.2-70.8); clinical benefit rate was 43.5% (95%CI: 29.1-57.8). CA 19-9 serum levels were decreased by > 25% as compared to baseline in 14/23 evaluable patients (63.6%). Treatment was well-tolerated, with skin rash being the most powerful predictor of both longer PFS (P < 0.0001) and OS (P = 0.01) at multivariate analysis (median OS for patients with or without rash: 42 wk vs 15 wk, respectively, Log-rank P = 0.03). Additional predictors of better outcome were: CA 19-9 reduction, female sex (for
文摘The paper presents the key milestones and outcomes of 65-year studies of the carcinogenic consequences of accidental radiation exposure of the population of the Ural region.The radioactive contamination of the Techa River and the 1957 accident at the Mayak Production Association were the reasons of the long-term population exposure at a wide dose-range.The most important tasks of the study were the reconstruction of individual doses,follow-up of the solid cancer and leukemia incidence and mortality among cohort members.The research results have shown that chronic human exposure,in comparison to acute exposure,does not reduce the risk of developing malignant tumors and leukemias.The value of the dose-rate factor does not exceed"one".Thus,according to our data,the Publication 103 of the International Commission on Radiological Protection seemed to underestimate the radiation risk of malignant tumors and leukemias in case of low dose-rate exposure of the population by a factor of two.Prospects for further radio-epidemiological studies in the Urals are associated with the analysis of the cohort of Southern Urals Populations Exposed to Radiation,which includes about 63 thousand exposed people and makes it possible to assess the radiation risk of solid cancers of certain localizations,certain types of leukemia,and non-cancer effects.
基金Wu Jie-ping Medical Foundation (No. 320.6720.0501)Shenzhen Science Technology Foundation (No. 200404093)
文摘Objective: To investigate the change of ATM phosphorylation in HepG2 cells and its effect on HepG2 cell survival under a continuous low dose-rate irradiation. Methods: HepG2 cells were exposed to equivalent doses of irradiation deliv- ered at either a continuous low dose-rate (7.76 cGy/h) or a high dose-rate (4500 cGy/h). The ATM phosphorylated proteins and surviving fraction of HepG2 cell after low dose-rate irradiation were compared with that after equivalent doses of high dose-rate irradiation. Results: The phosphorylation of ATM protein was maximal at 0.5 Gy irradiation delivered at either a high dose-rate or a continuous low dose-rate. As the radiation dose increased, the phosphorylation of ATM protein decreased under continuous low dose-rate irradiation. However, the phosphorylation of ATM protein was remained stable under high dose-rate irradiation. When the phosphorylation of ATM protein under continuous low dose-rate irradiation was equal to that under high dose-rate irradiation, there was no significant difference in the surviving fraction of HepG2 cells between two ir- radiation methods (P > 0.05). When the phosphorylation of ATM protein significantly decreased after continuous low dose-rate irradiation compared with that after high dose-rate irradiation, increased amounts of cell killing was found in low dose-rate irradiation (P < 0.01). Conclusion: Continuous low dose-rate irradiation increases HepG2 cells radiosensitivity compared with high dose-rate irradiation. The increased amounts of cell killing following continuous low dose-rate exposures are associated with reduced ATM phosphorylated protein.
