Parallel FIM Approach on GPU using OpenCL

In this paper, we describe GPU-Eclat algorithm, a GPU (General Purpose Graphics Processing Unit) enhanced implementation of Frequent Item set Mining (FIM). The frequent itemsets are extracted from a transactional database as it is a essential assignment in data mining field because of its broad applications in mining association rules, time series, correlations etc. The Eclat approach is the typically generate-and-check approach to obtain frequent itemsets from a database with a given minimum support threshold value. OpenCL is a platform independent Open Computing Language for GPU computation. We tested our implementation with an Radeon Dual graphic processor and determine up to 68X speedup as compared with sequential Eclat algorithm on a CPU. In order to map the Eclat algorithm onto the SIMD (Single Instruction Multiple Data) execution model, an array data structure is used to represent the input database and standard dataset is converted to the vertical data layout. In our implementation, we perform a parallelized version of the candidate generation and support counting phases on the GPU. Experimental results show that GPU-Eclat consistently outperforms CPU-based Eclat implementations. Our results reveal the potential for GPGPUs in speeding up data mining algorithms

Formulation and evaluation of microspheres containing ropinirole hydrochloride using biodegradable polymers

The present work relates with developing long acting sustain release microspheres of ropinirole hydrochloride (RPN) for treatment of Parkinson′s disease, that will sustain drug release up to 1 month. Biodegradable microspheres of RPN were prepared by using two different polymers (poly lactic co glycolic acid [PLGA] 50:50 and PLGA 75:25) employing double emulsion (W/O/W) solvent evaporation method. Preliminary optimization of process parameter was done for concentration of polyvinyl alcohol (PVA) solution, stirring speed, temperature of PVA solution, ratio of the drug to polymer (D/P) and ratio of internal phase to external phase volume (IP/EP). All formulations were evaluated for particle size, percentage yield, entrapment efficiency (EE), shape etc. Formulation E3 and E4 shows maximum EE. % in vitro drug release per day of E3 and E4 batch was studied. The RPN was incorporated successfully in microspheres prepared with 0.5% w/v PVA at 8000 RPM stirring speed, 20°C processing temperature, 1:4 drug polymer ratio and 1:30 IP/EP ratio, which provides sustained release up to 4 weeks with better efficacy and patient compliance and can be employed as an alternative to existing oral medications

Formulation and development of self-microemulsifying drug delivery system of pioglitazone hydrochloride

Self-microemulsifying drug delivery system (SMEDDS) is a promising system for the Biopharmaceutics Classification System (BCS) class II drugs. The current research aimed to improve the dissolution of poorly water-soluble antidiabetic drug pioglitazone HCl by formulating it in SMEDDS. Liquid SMEDDS of pioglitazone HCl were formulated with Capmul MCM C8 and oleic acid as oil phase, Cremophor RH 40 and Tween 80 as surfactant phase, and Transcutol P as cosurfactant phase after screening various vehicles. The prepared formulations were evaluated for self-emulsifying ability and phase diagram was constructed to optimize the system. These systems were further characterized for globule size, effect of pH and robustness, zeta potential, drug content, viscosity, self-emulsification time, polydispersity index, % transmittance, thermodynamic stability, surface morphology, and drug release. The system was robust to different pH media and dilution volumes. The optimized system possessed a mean globule size of 122.2 nm, zeta potential around -22.9 mV, drug content 99.66 ± 0.47%, viscosity 0.8874 ± 0.026 cP, emulsification time 38 s, polydispersity index value of 0.5, and transmittance value of 99.3 ± 0.6%. Drug release in hydrochloric acid buffer pH 2 was found to be 99.35 ± 0.38%. More than three-fold increase in dissolution characteristics of pioglitazone HCl in SMEDDS was observed as compared to pure and marketed formulation. Liquid SMEDDS filled in hard gelatin capsule (HGC) shell was found to be compatible. Stability studies show there was no sign of phase separation or precipitation and no change in drug content was observed

Dosimetric validation of new semiconductor diode dosimetry system for intensity modulated radiotherapy

Introduction: The new diode Isorad was validated for intensity modulated radiotherapy (IMRT) and the observations during the validation are reported. Materials and Methods: The validation includes intrinsic precision, post-irradiation stability, dose linearity, dose-rate effect, angular response, source to surface (SSD) dependence, field size dependence, and dose calibration. Results: The intrinsic precision of the diode was more than 1% (1 σ). The linearity found in the whole range of dose analyzed was 1.93% (R 2 = 1). The minimum and maximum variation in the measured and calculated dose were found to be 0.78% (with 25 MU at ioscentre) and 4.8% (with 1000 MU at isocentre), respectively. The maximal variation in angular response with respect to arbitrary angle 0° found was 1.31%. The diode exhibited a 51.7% and 35% decrease in the response in the 35 cm and 20 cm SSD range, respectively. The minimum and the maximum variation in the measured dose from the diode and calculated dose were 0.82% (5 cm × 5 cm) and 3.75% (30 cm × 30 cm), respectively. At couch 270°, the response of the diode was found to vary maximum by 1.4% with ΁ 60 gantry angle. Mean variation between measured dose with diode and planned dose by TPS was found to be 1.3% (SD 0.75) for IMRT patient-specific quality assurance. Conclusion: For the evaluation of IMRT, use of cylindrical diode is strongly recommended

Measurement of total scatter factor for stereotactic cones with plastic scintillation detector

Advanced radiotherapy modalities such as stereotactic radiosurgery (SRS) and image-guided radiotherapy may employ very small beam apertures for accurate localized high dose to target. Accurate measurement of small radiation fields is a well-known challenge for many dosimeters. The purpose of this study was to measure total scatter factors for stereotactic cones with plastic scintillation detector and its comparison against diode detector and theoretical estimates. Measurements were performed on Novalis Tx™ linear accelerator for 6MV SRS beam with stereotactic cones of diameter 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm. The advantage of plastic scintillator detector is in its energy dependence. The total scatter factor was measured in water at the depth of dose maximum. Total scatter factor with plastic scintillation detector was determined by normalizing the readings to field size of 10 cm × 10 cm. To overcome energy dependence of diode detector for the determination of scatter factor with diode detector, daisy chaining method was used. The plastic scintillator detector was calibrated against the ionization chamber, and the reproducibility in the measured doses was found to be within ± 1%. Total scatter factor measured with plastic scintillation detector was 0.728 ± 0.3, 0.783 ± 0.05, 0.866 ± 0.55, 0.885 ± 0.5, and 0.910 ± 0.06 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. Total scatter factor measured with diode detector was 0.733 ± 0.03, 0.782 ± 0.02, 0.834 ± 0.07, 0.854 ± 0.02, and 0.872 ± 0.02 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. The variation in the measurement of total scatter factor with published Monte Carlo data was found to be −1.3%, 1.9%, −0.4%, and 0.4% for cone sizes of 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. We conclude that total scatter factor measurements for stereotactic cones can be adequately carried out with a plastic scintillation detector. Our results show a high level of consistency within our data and compared well with published data

Peripheral dose measurements with diode and thermoluminescence dosimeters for intensity modulated radiotherapy delivered with conventional and un-conventional linear accelerator

The objective of this paper was to measure the peripheral dose (PD) with diode and thermoluminescence dosimeter (TLD) for intensity modulated radiotherapy (IMRT) with linear accelerator (conventional LINAC), and tomotherapy (novel LINAC). Ten patients each were selected from Trilogy dual-energy and from Hi-Art II tomotherapy. Two diodes were kept at 20 and 25 cm from treatment field edge. TLDs (LiF:MgTi) were also kept at same distance. TLDs were also kept at 5, 10, and 15 cm from field edge. The TLDs were read with REXON reader. The readings at the respective distance were recorded for both diode and TLD. The PD was estimated by taking the ratio of measured dose at the particular distance to the prescription dose. PD was then compared with diode and TLD for LINAC and tomotherapy. Mean PD for LINAC with TLD and diode was 2.52 cGy (SD 0.69), 2.07 cGy (SD 0.88) at 20 cm, respectively, while at 25 cm, it was 1.94 cGy (SD 0.58) and 1.5 cGy (SD 0.75), respectively. Mean PD for tomotherapy with TLD and diode was 1.681 cGy SD 0.53) and 1.58 (SD 0.44) at 20 cm, respectively. The PD was 1.24 cGy (SD 0.42) and 1.088 cGy (SD 0.35) at 25 cm, respectively, for tomotherapy. Overall, PD from tomotherapy was found lower than LINAC by the factor of 1.2-1.5. PD measurement is essential to find out the potential of secondary cancer. PD for both (conventional LINAC) and novel LINACs (tomotherapy) were measured and compared with each other. The comparison of the values for PD presented in this work and those published in the literature is difficult because of the different experimental conditions. The diode and TLD readings were reproducible and both the detector readings were comparable

Doping-Induced Room Temperature Stabilization of Metastable β‑Ag₂WO₄ and Origin of Visible Emission in α- and β‑Ag₂WO₄: Low Temperature Photoluminescence Studies

A new strategy of synthesizing hexagonal metastable β-Ag₂WO₄ at room temperature based on aliovalent Eu³⁺ doping induced orthorhombic-to-hexagonal phase transition using coprecipitation method is offered. Both α-Ag₂WO₄ and β-Ag₂WO₄ phase were characterized systematically using X-ray diffraction (XRD), Raman spectroscopy, Fourier transformed infrared spectroscopy (FTIR), and time-resolved photoluminescence (TRPL). Emission spectra at low temperature (77K) show two clear bands in the case of α-Ag₂WO₄ and β-Ag₂WO₄, which are designated as PL1 (low wavelength region) and PL2 (high wavelength region). PL1 (∼430–440 nm) is attributed to charge transfer transition within tungsten octahedra in α-Ag₂WO₄ where as it is attributed to a similar transition within the tungsten tetrahedral in β-Ag₂WO₄. Temperature-dependent studies showed that origin of PL2 emission in α-Ag₂WO₄ and β-Ag₂WO₄ might be different. PL2 in the case of α-Ag₂WO₄ is because of presence of F⁺ center (singly ionized oxygen vacancy) within the band gap which is supported by density function theory measurement (DFT). Doping Eu³⁺ in α-Ag₂WO₄ diminishes PL2 emission. Lifetime measurement supports that, in the case of β-Ag₂WO₄, both PL1 and PL2 might have common origin, i.e., charge transfer transition