On the quantum and classical scattering times due to charged dislocations in an impure electron gas

We derive the ratio of transport and single particle relaxation times in three and two - dimensional electron gases due to scattering from charged dislocations in semiconductors. The results are compared to the respective relaxation times due to randomly placed charged impurities. We find that the ratio is larger than the case of ionized impurity scattering in both three and two-dimensional electron transport.Comment: 4 pages, 3 figure

The synthesis of TiO2 thin film by Chemical Bath Deposition (CBD) method

Titanium oxide (TiO2) films have several advantages for applications in solar cells and very commonly used as a photo-catalyst for degradation of environmental pollutants. In this study, TiO2 films were synthesized using, a simple, less expensive, low temperature and convenient for large area deposition method, a chemical bath deposition (CBD) and their structural and optical properties were examined at various calcinations temperatures. The X-ray diffraction (XRD) technique shows the presence of the picks characteristic of anatase phase after annealing our films at 500°C, 600°C and rutile phase appears after heat treatment at 700°C. The surface morphology of the deposited films was characterized by the FEG scanning electronic microscopy (FEGSEM) and atomic force microscopy (AFM). Energy dispersive X-ray spectroscopy (EDS) analysis was used to determine the chemical composition of the prepared films. The UV-Vis-NIR spectroscopy shows that the film exhibits a transmission around 60%. The indirect band gap of the deposited films was between 2.88 and 3.22 eV

Acute myeloid leukemia in the elderly (age 70 yr or older): long-term survivors

International audienceOBJECTIVE: Little data exist regarding long-term survival in elderly patients with acute myeloid leukemia (AML). METHODS: In view of the fact that most deaths occurred during the first 3 yr, this study examined long-term survival in this patient population, defined as overall survival for at least 3 yr with the aim to determine the number of long-term survivors and to identify factors that might impact on longer survival. RESULTS: The criterion for entry into this cohort was fulfilled by 57 patients among 302 seen over a 14-yr period (19%): 12 patients who never achieved complete remission (CR), 21 patients who relapsed after CR achievement, and 24 patients who achieved CR and did not relapse, including three patients who died while in CR and 21 patients still alive in first CR at the time of analysis. The pretreatment prognostic importance of cytogenetics was still apparent. However, some patients with secondary AML and/or unfavorable-risk markers belonged to long survivors. The cohort involved mainly patients treated by intensive chemotherapy, but also some patients receiving low-intensity therapies. CONCLUSION: Improved results should come from a better selection of patients to a more 'personalized' therapeutic approach combined with better supportive care assessmen

Deep Centers In Semi-Insulating Current Topics In Solid State Physics Fe-Doped Native GaN Substrates Grown By Hydride Vapour Phase Epitaxy

Electrical properties, Fe concentration, and deep centers in semi-insulating Fe-doped GaN substrates grown by hydride vapor phase epitaxy (HVPE) were characterized by temperature-dependent Hall-effect measurements, secondary ion mass spectroscopy, and thermally stimulated current (TSC) spectroscopy, Five adjacent samples from a low-[Fe] wafer displayed very high resistivity, dominated by a center at 0,94 eV. At least six traps were observed in the samples by TSC, with trap (0.56-0.60 eV) being dominant. A metastable trap A, at similar to 0.82 eV appeared after white-light illumination at 300 K-A sample from a high-[Fe] wafer displayed a lower resistivity, dominated by a center at 0,58 eV. The largest TSC peak in this sample was trap A(1), although trap B also appeared. These TSC traps are compared with deep-level-transient- spectroscopy traps reported in conductive epitaxial and bulk HVPE-GaN

Deep Centers In Semi-Insulating Current Topics In Solid State Physics Fe-Doped Native GaN Substrates Grown By Hydride Vapour Phase Epitaxy

Electrical properties, Fe concentration, and deep centers in semi-insulating Fe-doped GaN substrates grown by hydride vapor phase epitaxy (HVPE) were characterized by temperature-dependent Hall-effect measurements, secondary ion mass spectroscopy, and thermally stimulated current (TSC) spectroscopy, Five adjacent samples from a low-[Fe] wafer displayed very high resistivity, dominated by a center at 0,94 eV. At least six traps were observed in the samples by TSC, with trap (0.56-0.60 eV) being dominant. A metastable trap A, at similar to 0.82 eV appeared after white-light illumination at 300 K-A sample from a high-[Fe] wafer displayed a lower resistivity, dominated by a center at 0,58 eV. The largest TSC peak in this sample was trap A(1), although trap B also appeared. These TSC traps are compared with deep-level-transient- spectroscopy traps reported in conductive epitaxial and bulk HVPE-GaN

Treatment with Low-Dose Cytarabine in Elderly Patients (Age 70 Years or Older) with Acute Myeloid Leukemia: A Single Institution Experience

International audienceOBJECTIVES: Low-dose cytarabine (LD-AraC) is still regarded as the standard of care in elderly patients with acute myeloid leukemia (AML) 'unfit' for intensive chemotherapy. In this study, we reported our experience with LD-AraC in patients \textgreater/= 70 years old and compared the results to those of intensive chemotherapy, best supportive care (BSC), or hypomethylating agents in the same age population. METHODS: Between 2000 and 2014, 60 patients received LD-AraC at 20 mg once or twice daily by subcutaneous injection for 10 consecutive days every 4-6 weeks. RESULTS: Complete remission rate with LD-AraC was 7% versus 56% with intensive chemotherapy and 21% with hypomethylating agents. Median overall survival (OS) of patients treated with LD-AraC was 9.6 months with 3-year OS of 12%. Survival with LD-AraC was better than with BSC only (P = 0.001). Although not statistically significant, intensive chemotherapy and hypomethylating agents tended to be better than LD-AraC in terms of OS (median: 12.4 months and 16.1 months, respectively). There was no clear evidence that a beneficial effect of LD-AraC was restricted to any particular subtype of patients, except for cytogenetics. There was a trend for a better OS in LD-AraC treated patients in the setting of clinical trials as compared with those treated outside of a clinical trial. CONCLUSIONS: Despite a trend in favor of intensive chemotherapy and hypomethylating agents over LD-AraC, no real significant advantage could be demonstrated, while LD-AraC showed a significant advantage comparatively to BSC. All this tends to confirm that LD-AraC can still represent a baseline against which new promising agents may be compared either alone or in combinatio

Treatment patterns and comparative effectiveness in elderly acute myeloid leukemia patients (age 70 years or older): the Lyon-university hospital experience

International audienceThe treatment of very elderly patients (\textgreater/=70 years) with acute myeloid leukemia remains controversial. We present here 302 patients seen over a 14-year period in order to understand the real-world treatment patterns and outcomes in this patient population. Less than 25% of patients achieved a complete remission. The median overall survival was 12.4, 11.5 and 2.6 months, with a 3-year rates of 27%, 17% and 6%, for non-acute promyelocytic leukemia patients receiving intensive chemotherapy, lower-intensity therapy or best supportive care (BSC), respectively. In all ages, results were not significantly different among patients receiving low-intensity therapy and intensive chemotherapy, but significantly worse in those treated with BSC only. Similarly, intensive chemotherapy and low-intensity therapy gave better survival rates than BSC in patients with favorable- or intermediate-risk cytogenetics and in those with unfavorable cytogenetics (p \textless 0.0001 and p = 0.04, respectively