17 research outputs found

    Equivalent dose in 2 Gy (EQD2) to pelvic lymph nodes using volume based prescription for three brachytherapy applicators — a dosimetric retrospective analysis

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    BACKGROUND: Pelvic lymph node (PLN) metastasis has been included in the FIGO staging, so there is a need to determine the dose contribution from brachytherapy to ascertain the total delivered dose to the pelvic lymph nodes in cervical cancer. The aim of the study was to calculate the equivalent dose in 2 Gy (EQD2) of the pelvic lymph nodes (PLNs) based on volume prescription using three applicators. Materials and methods: Forty-one patients who had undergone external beam radiotherapy followed by brachytherapy using tandem ovoids (TO), tandem ring (TR) and TO + free hand interstitial needles (TO + FH) applicators were taken for this study. 26 Gy in 4 fractions was prescribed to HRCTV. The external iliac node (ELN), internal iliac node (ILN) and obturator (OBT) were contoured and the median EQD2 of the lymph nodes was calculated. RESULTS: The median bilateral EQD2 values of ELN were 1.55 Gy (TR), 1.75 Gy (TO), 1.9 Gy (TO + FH), of ILN these were 2.57 Gy (TR), 3.27 Gy (TO), 3.04 Gy (TO + FH), and of OBT these were 3.69 Gy (TR), 4.46 Gy (TO), 4.69 Gy (TO + FH), respectively. The total median EQD2 values of TR, TO and TO + FH were 52.71 Gy, 53.03 Gy, and 53.88–62.73 Gy, respectively. CONCLUSION: Our study calculated the median EQD2 to the pelvic lymph nodes using three types of applicators in brachytherapy. This could serve as reference to decide on the EBRT boost dose while treating patients with enlarged pelvic lymph nodes

    Room Temperature-Processed TiO2 MIM Capacitors for DRAM Applications

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    We report the room temperature fabrication of Ta/TiO2/Ta metal-insulator-metal (MIM) capacitors (mainly, for DRAM applications). The fabricated devices show high capacitance density (similar to 15 fF/mu m(2)), and low leakage current density of 6.4 X 10(-8) A/cm(2) (27 degrees C) and 3.3 x 10(-6) A/cm(2) (125 degrees C) at -1 V. We analyze the electrical and material characteristics of the fabricated capacitors, and compare the device performance of these capacitors with other TiO2 and TiO2-based MIM capacitors reported in recent literature

    High-Performance Metal-Insulator-Metal Capacitors Using Europium Oxide as Dielectric

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    We report the first demonstration of metal-insulator-metal (MIM) capacitors with Eu2O3 dielectric for analog and DRAM applications. The influence of different anneal conditions on the electrical characteristics of the fabricated MIM capacitors is studied. FG anneal results in high capacitance density (7 fF/mu m(2)), whereas oxygen anneal results in low quadratic voltage coefficient of capacitance (VCC) (194 ppm/V-2 at 100 kHz), and argon anneal results in low leakage current density (3.2 x 10(-8) A/cm(2) at -1 V). We correlate these electrical results with the surface chemical states of the films through X-ray photoelectron spectroscopy measurements. In particular, FG anneal and argon anneal result in sub-oxides, which modulate the electrical properties

    Performance and reliability of Gd2O3 and stacked Gd2O3-Eu2O3 metal-insulator-metal capacitors

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    Gd2O3-based metal-insulator-metal capacitors have been characterized with single layer (Gd2O3) and bilayer (Gd2O3/Eu2O3 and Eu2O3/Gd2O3) stacks for analog and DRAM applications. Although single layer Gd2O3 capacitors provide highest capacitance density (15 fF/mu m(2)), they suffer from high leakage current density, poor capacitance density-voltage linearity, and reliability. The stacked dielectrics help to reduce leakage current density (1.2x10(-5) A/cm(2) and 2.7 x 10(-5) A/cm(2) for Gd2O3/Eu2O3 and Eu2O3/Gd2O3, respectively, at -1 V), improve quadratic voltage coefficient of capacitance (331 ppm/V-2 and 374 ppm/V-2 for Gd2O3/Eu2O3 and Eu2O3/Gd2O3, respectively, at 1 MHz), and improve reliability, with a marginal reduction in capacitance density. This is attributed to lower trap heights as determined from Poole-Frenkel conduction mechanism, and lower defect density as determined from electrode polarization model

    Mitochondrial DNA variations and mitochondrial dysfunction in Fanconi anemia.

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    In-vitro studies with different Fanconi anemia (FA) cell lines and FANC gene silenced cell lines indicating involvement of mitochondria function in pathogenesis of FA have been reported. However, in-vivo studies have not been studied so far to understand the role of mitochondrial markers in pathogenesis of FA. We have carried out a systematic set of biomarker studies for elucidating involvement of mitochondrial dysfunction in disease pathogenesis for Indian FA patients. We report changes in the mtDNA number in 59% of FA patients studied, a high frequency of mtDNA variations (37.5% of non-synonymous variations and 62.5% synonymous variations) and downregulation of mtDNA complex-I and complex-III encoding genes of OXPHOS (p0.05, Beclin-1; p>0.05, and MAP1-LC3, p<0.05) has also been observed, suggesting inability of FA cells to clear off impaired mitochondria. We hypothesize that accumulation of such impaired mitochondria in FA cells therefore may be the principal cause for bone marrow failure (BMF) and a plausible effect of inefficient clearance of impaired mitochondria in FA

    Is the Ratio of Antibodies Against Oxidized LDL to Oxidized LDL an Indicator of Cardiovascular Risk in Psoriasis?

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    Objectives: Psoriasis is a chronic inflammatory skin disease. Chronic inflammation results in increased oxidative stress and oxidizes lipoproteins, increasing their atherogenicity. This study sought to estimate the levels of oxidized low-density lipoprotein (ox-LDL) and antibodies against oxidized LDL (anti-ox-LDL) and compute the ratio of anti-ox-LDL/ox-LDL as a single composite parameter to assess the oxidative lipoprotein burden as an indicator of cardiovascular risk in patients with psoriasis. Methods: This cross-sectional study included 45 patients with psoriasis. All patients were given a psoriasis severity index score and their ox-LDL and anti-ox-LDL estimated using ELISA. Results: The results of this study show an elevation in the ratio of anti-ox-LDL to ox-LDL in patients with psoriasis, which initiate and perpetuate the pathogenesis of psoriasis and its comorbidity, atherosclerotic cardiovascular disease. Conclusions: Our results suggest that an elevated ratio of anti-ox-LDL/ox-LDL can serve as a composite parameter reflecting the total oxidative lipoprotein burden and cardiovascular risk in psoriasis patients

    Performance and Reliability of TiO2/ZrO2/TiO2 (TZT) and AlO-Doped TZT MIM Capacitors

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    Metal-insulator-metal capacitors for dynamic random access memory applications have been realized using TiO2/ZrO2/TiO2 (TZT) and AlO-doped TZT TiO2/ZrO2/AlO/ZrO2/TiO2 (TZAZT) and TiO2/ZrO2/AlO/ZrO2/AlO/ZrO2/TiO2 (TZAZAZT)] dielectric stacks. High-capacitance densities of 46.6 fF/mu m(2) (for TZT stacks), 46.2 fF/mu m(2) (for TZAZT stacks), and 46.8 fF/mu m(2) (for TZAZAZT stacks) have been achieved. Low leakage current densities of about 4.9 x 10(-8), 5.5x10(-9), and 9.7x10(-9) A/cm(2) (at -1 V) have been obtained for TZT, TZAZT, and TZAZAZT stacks, respectively. We analyze the leakage current mechanisms at different electric field regimes, and compute the trap levels. The effects of constant voltage stress on the device characteristics were studied, and excellent device reliability was demonstrated. The electrical characteristics of the devices were correlated with the structural analysis through X-ray diffraction measurements and the surface chemical states analysis through X-ray photoelectron spectroscopy measurements. The doped-dielectric stacks (AlO-doped TZT: TZAZT and TZAZAZT) help to reduce leakage current density and improve reliability, without substantial reduction in capacitance density, compared with their undoped counterparts (TZT)

    High-Performance Stacked TiO2-ZrO2 and Si-doped ZrO2 Metal-Insulator-Metal Capacitors

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    Metal-insulator-metal (MIM) capacitors for DRAM applications have been realised using stacked TiO2-ZrO2 (TiO2/ZrO2 and ZrO2/TiO2) and Si-doped ZrO2 (TiO2/Si-doped ZrO2) dielectrics. High capacitance densities (> 42 fF/mu m(2)), low leakage current densities (< 5 x 10(-7) A/cm(2) at -1 V), and sub-nm EOT (< 0.8 nm) have been achieved. The effects of constant voltage stress on the device characteristics is studied. The structural analysis of the samples is performed by X-ray diffraction measurements, and this is correlated to the electrical characteristics of the devices. The surface chemical states of the films are analyzed through X-ray photoelectron spectroscopy measurements. The doped-dielectric stack (TiO2/Si-doped ZrO2) helps to reduce leakage current density and improve reliability, with a marginal reduction in capacitance density; compared to their undoped counterparts (TiO2/ZrO2 and ZrO2/TiO2). We compare the device performance of the fabricated capacitors with other stacked high-k MIM capacitors reported in recent literature

    Glycemic and insulin responses to some breakfast items in diabetic subjects

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    The glycaemic and insulin responses to four common breakfast items namely iddli, pongali uppuma and bread were studied in South Indian non-insulin dependent diabetic subjects and compared with 75 gms of glucose. The breakfasts- provided 300 K cals of which complex carbohydrate contributed 68-81%, proteins 12-14% and fat 8-19% of total calories, while the dietary fibre contents varied from 3.8 g to 7.4 g in 300 K ca1 portions. The results indicated that pongal, uppuma and iddli were suitable for diabetics as jiheir glycaemic responses to the test foods were low. Bread was considered unsuitable as its glycaemic response was as high as that of glucose. A number of parameters like the mode of cooking and' processing, the form of food and the differences in food constituents which affect digestion, absorption and metabolism seem to influence the glycaemic and insulin responses
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