Modified transform-based gamma correction for MRI tumor image denoising and segmentation by optimized histon-based elephant herding algorithm

Medical image processing is typically performed to diagnose a patient's brain tumor prior to surgery. In this study, a technique in denoising and segmentation was developed to improve medical image processing. The proposed approach employs multiple modules. In the first module, the noisy brain tumor image is transformed into multiple low- and high-pass tetrolet coefficients. In the second module, multiple low-pass tetrolet coefficients are applied through a modified transform-based gamma correction method. Generalized cross-validation is used on multiple high-pass tetrolet coefficients to obtain the best threshold value. In the third module, all enhanced coefficients are applied to the partial differential equation method. In the final module, the denoised image is applied to Atanassov's intuitionistic fuzzy set histon-based fuzzy clustering method with centroid optimization using an elephant herding method. Accordingly, the tumor part is segmented from the nontumor part in the magnetic resonance imaging brain images. The method was assessed in terms of peak signal-to-noise ratio, mean square error, specificity, sensitivity, and accuracy. The experimental results showed that the suggested method is superior to traditional methods.     

Mixed Convection of Water at 4 °C Along a Wedge with Variable Surface Temperature in a Porous Medium

In this study, the mixed convection of water at 4 °C along a wedge in a porous medium is investigated numerically using a finite difference method. To explore the effect of mixed convection, both forced and free convection-dominated regimes are considered. Non-similarity solutions are obtained for the variable walltemperature boundary condition. Velocity and temperature profiles as well as local dimensionless skin friction and the Nusselt number are obtained and compared with available numerical results for various values of different parameters. The wedge angle geometry parameter m and mixed convection parameter ξ ranged from 0 to 1 in both regimes, whereas different values of λ are considered for the purpose of comparison of heat transfer results.     

Sparsity-motivated automatic target recognition

We present an automatic target recognition algorithm using the recently developed theory of sparse representations and compressive sensing. We show how sparsity can be helpful for efficient utilization of data for target recognition. We verify the efficacy of the proposed algorithm in terms of the recognition rate and confusion matrices on the well known Comanche (Boeing-Sikorsky, USA) forward-looking IR data set consisting of ten different military targets at different orientations.     

Quantitative structured-illumination phase microscopy

We introduce a quantitative phase imaging method for homogeneous objects with a bright field transmission microscope by using an amplitude mask and a digital processing algorithm. A known amplitude pattern is imaged on the sample plane containing a thick phase object by placing an amplitude mask in the field diaphragm of the microscope. The phase object distorts the amplitude pattern according to its optical path length (OPL) profile, and the distorted pattern is recorded in a CCD detector. A digital processing algorithm then estimates the object's quantitative OPL profile based on a closed form analytical solution, which is derived using a ray optics model for objects with small OPL gradients.     

Improving post irradiation stability of high density polyethylene by multi walled carbon nanotubes

Sterilization of implants and other clinical accessories is an integral part of any medical application. Although many materials are used as implants, polyethylene stands unique owing to its versatility. Carbon nanotubes are being used as a filler material to enhance the properties of polyethylene. However, the role of multi walled carbon nanotubes (MWCNTs) as an effective antioxidant and radical scavenger in resisting the deteriorating effects of sterilization is yet to be studied in detail. The present work is aimed to investigate the mechanical properties and oxidation stability of irradiated high density polyethylene (HDPE) reinforced by MWCNTs with various concentrations such as 0.25%, 0.50%, 0.75% and 1.00 wt.%. The composites were exposed to ⁶⁰Co source in air and irradiated at different dosage level starting from 25 to 100 kGy and then shelf aged for a period of 120 days prior to investigation. The loss in toughness, Young’s modulus and ultimate strength at 100 kGy for 1 wt.% MWCNTs composite were found to be 21.5%, 20.3% and 19.2%, respectively compared to that of unirradiated composite. FTIR and ESR studies confirmed the antioxidant and radical scavenging potentialities of MWCNTs with increased concentration and irradiation dosage. It was found that by the addition of 1 wt.% MWCNTs into virgin HDPE, the oxidation index of the composite at 100 kGy was decreased by 56.2%. It is concluded that the addition of MWCNTs into polyethylene not only limits the loss of mechanical properties but also improves its post irradiation oxidative stability.     

Exfoliation of clay layers in polypropylene matrix using potassium succinate-g-polypropylene as compatibilizer

The efficiency of potassium succinate-g-polypropylene (KPPSA) as compatibilizer for the dispersion of clay in a high molecular weight polypropylene during melt mixing for the preparation of nanocomposites was evaluated and compared with maleic anhydride-g-polypropylene (PPMA). Nanocomposites were prepared by direct melt mixing and by masterbatch methods and the structure obtained was characterized by WAXD and TEM. The exfoliation and better dispersion of the organoclay was observed with KPPSA than PPMA. The dispersion of clay was found to be dependent on the method of preparation, type and the amount of compatibilizer used. The dispersion was better when the nanocomposites were prepared by two step masterbatch route than the single step direct mixing method. Flexural moduli and crystallization behavior were studied and correlated with the dispersion of organoclay in the PP matrix.     

Environmental radioactivity studies in the proposed Lambapur and Peddagattu uranium mining areas of Andhra Pradesh, India

The present work was aimed at the establishment of baseline radioactive data in the proposed Lambapur and Peddagattu uranium mining areas in the Andhra Pradesh state, India. The background concentrations of naturally occurring radioactivity in the near-surface soils of the study areas were estimated and the results were analysed. The (238)U concentration in the near-surface soil of the study area was found to vary from 100 to 176 Bq kg(-1), with a mean of 138±24 Bq kg(-1). (232)Th in the study area soils was found to vary between 64 and 116 Bq kg(-1), with a mean of 83±15 Bq kg(-1). The (40)K concentration was found to vary between 309 and 373 Bq kg(-1), with a mean of 343±20 Bq kg(-1). The mean natural background radiation levels were also measured with thermoluminescence (TL) dosimetry technique and with a μR-survey meter, in the villages of the study area. Dose rates measured by TL are found to vary from 1287 to 3363 μGy y(-1), with a mean of 2509 ± 424 μGy y(-1). The dose rates measured in the same villages with a μR-survey meter were found to be in the range of 1211-3255 μGy y(-1), with a mean of 2524 ± 395 μGy y(-1). The mean radiation levels in the study area are found to be relatively high when compared with (Indian) national and international averages. Correlations among radon, thoron and gamma dose rates were found to be poor. The pre-operational data produced in this work will be useful for comparison with future radiation levels during the proposed uranium mining operations.     

Effect of nerodilol and carvone on in vitro permeation of nicorandil across rat epidermal membrane

The objective of the study was to investigate the effect of nerodilol and carvone on the in vitro transdermal delivery of nicorandil so as to fabricate a membrane-moderated transdermal therapeutic system. The in vitro permeation studies were carried across the rat epidermal membrane from the hydroxypropyl methylcellulose (HPMC) gels (prepared with 70:30 v/v ethanol-water) containing selected concentrations of a terpene such as nerodilol (0% w/w, 4% w/w, 8% w/w, 10% w/w, or 12% w/w) or carvone (0% w/w, 4% w/w, 8% w/w, 12% w/w, or 16% w/w). The amount of nicorandil permeated (Q₂₄) from HPMC gel drug reservoir without a terpene was 3424.6 ± 51.4 μg/cm², and the corresponding flux of the drug was 145.5 ± 2.2 μg/cm²· h. The flux of nicorandil increased with an increase in terpene concentration in HPMC gel. It was increased ranging from 254.9 ± 3.1 to 375.7 ± 3.2 μg/cm²·h or 207.6 ± 4.7 to 356.7 ± 15.3 μg/cm²· h from HPMC gels containing nerodilol (4% w/w to 12% w/w) or carvone (4% w/w to 16% w/w), respectively. Nerodilol increased the flux of nicorandil by about 2.62-folds whereas carvone increased the flux of the drug by about 2.49-folds across the rat epidermal membrane. The results of the Fourier Transform Infrared (FT-IR) study indicated that the enhanced in vitro transdermal delivery of nicorandil might be due to the partial extraction of stratum corneum lipids by nerodilol or carvone. It was concluded that the terpenes, nerodilol and carvone, produced a marked penetration enhancing effect on the transdermal delivery of nicorandil that could be used in the fabrication of membrane-moderated transdermal therapeutic systems.     

Safety, pharmacokinetics and biodistribution studies of a beta-galactoside prodrug of doxorubicin for improvement of tumor selective chemotherapy

Anthracycline antibiotics, particularly doxorubicin (DOX) and daunorubicin, have been used extensively in the treatment of human malignancies. However, cardiotoxicity and multidrug resistance are significant problems that limit the clinical efficacy of such agents. Rational design to avoid these side effects includes strategies such as drug targeting and prodrug synthesis. The DOX prodrug N-(beta-D-glucopyranosylbenzyloxycarbonyl)-doxorubicin (prodrug 1) was synthesized for specific activation by beta-galactosidase, which is expected to release in necrotic areas of tumor lesions. Described here is the safety, pharmacokinetics, and biodistribution studies of a beta-galactoside prodrug of DOX. In vivo safety evaluation was done in the Ehrlich Ascites Carcinoma (EAC) tumor model. The dose of DOX was 8 mg/kg and the dose of prodrug was 8 mg/kg and 24 mg/kg of DOX equivalents. Our results on cytotoxicity, which demonstrated compression in the number of EAC cells and their viability, substantiate these data. Prodrug 1 was safe up to a dose of 24 mg/kg of DOX equivalents in EAC mice. The pharmacokinetics and biodistribution of prodrug (300 mg/kg) in normal mice were determined and compared with DOX (20 mg/kg). Administration of DOX in normal mice resulted in a peak plasma concentration of 19.45 microM (t = 30 minutes). Prodrug injection resulted in 3- to 16-fold lower concentrations in the tissues of normal mice. As it is more polar, lower levels were observed in tissues and plasma in contrast to the parent compound DOX. In vivo safety studies have shown that prodrug 1 had a maximum tolerated dose compared with DOX and led to improved pharmacokinetics in normal mice.     

Adsorption and desorption characteristics of lindane, carbofuran and methyl parathion on various Indian soils

Adsorption and desorption characteristics of three insecticides on four Indian soils were studied. Insecticides used were representative of organochlorine, organophosphate, and carbomate groups. The order of adsorption of pesticides on soils was: lindane > methyl parathion > carbofuran. Compost soil had shown the maximum adsorption capacity. The order of adsorption capacity of various soils were: compost soil > clayey soil > red soil > sandy soil. Adsorption isotherms were better fitted to Freundlich model and K_f values increased with increase in organic matter content of the soils. Thermodynamic parameters indicated favorable adsorption of all the three pesticides in four different soils. Adsorption was exothermic in nature. Distilled water desorbed 30–60% of adsorbed pesticides whereas; organic solvents were able to affect 50–80% of sorbed pesticides. Clay content and organic matter played a significant role in pesticide adsorption and desorption processes. Hysteresis effect was observed in red, clayey and compost soils. Hysteresis effect increased with increase in organic matter and clay content of the soils.