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To study 2D and 3D dosimetric values for bladder and rectum, and the influence of bladder volume on bladder dose in high dose rate (HDR) intracavitary brachytherapy (ICBT). The large patient data incorporated in this study would better represent the inherent variations in many parameters affecting dosimetry in HDR-ICBT.
Material and Methods:
We prospectively collected data for 103 consecutive cervical cancer patients (over 310 HDR fractions) undergoing CT-based HDR-ICBT at our centre. Correlation among bladder and rectum maximum volume doses and corresponding International Commission on Radiation Units and Measurement (ICRU) point doses were estimated and analysed. Impact of bladder volume on bladder maximum dose was assessed.
The ICRU point doses to bladder and rectum varied from the volumetric doses to these organs. Further, bladder volume poorly correlated with bladder maximum dose for volume variations encountered in the clinical practice at our centre.
ICRU point doses to bladder and rectum are less likely to correlate with long-term toxicities to these organs. Further, in clinical practice where inter-fraction bladder volume does not vary widely there is no correlation between bladder volume and bladder dose.
The burden of dengue virus infections increased globally during recent years. Though India is considered as dengue hyper-endemic country, limited data are available on disease epidemiology. The present study includes molecular characterization of dengue virus strains occurred in Hyderabad, India, during the year 2014. A total of 120 febrile cases were recruited for this study, which includes only children and 41 were serologically confirmed for dengue positive infections using non-structural (NS1) and/or IgG/IgM ELISA tests. RT-PCR, nucleotide sequencing and evolutionary analyses were carried out to identify the circulating serotypes/genotypes. The data indicated a high percent of severe dengue (63%) in primary infections. Simultaneous circulation of all four serotypes and co-infections were observed for the first time in Hyderabad, India. In total, 15 patients were co-infected with more than one dengue serotype and 12 (80%) of them had severe dengue. One of the striking findings of the present study is the identification of serotype Den-1 as the first report from this region and this strain showed close relatedness to the Thailand 1980 strains but not to any of the strains reported from India until now. Phylogenetically, all four strains of the present study showed close relatedness to the strains, which are reported to be high virulent.
Genetic diversity and relationship of 92 bread wheat (Triticum aestivum L.) genotypes from India and exotic collections were examined using simple sequence repeat (SSR) markers and phenotypic traits to identify new sources of diversity that could accelerate the development of improved wheat varieties better suited to meet the challenges posed by heat stress in India. Genetic diversity assessed by using 82 SSR markers was compared with diversity evaluated using five physiological and six agronomic traits under the heat stress condition. A total of 248 alleles were detected, with a range of two to eight alleles per locus. The average polymorphic information content value was 0.37, with a range of 0.04 (cfd9) to 0.68 (wmc339). The heat susceptibility index was determined for grain yield per spike, and the genotypes were grouped into four categories. Two dendrograms that were constructed based on phenotypic and molecular analysis using UPGMA (unweighted pair group method with arithmetic mean) were found to be topologically different. Genotypes characterized as highly heat tolerant were distributed among all the SSR-based cluster groups. This implies that the genetic basis of heat stress tolerance in these genotypes is different, thereby enabling wheat breeders to combine these diverse sources of genetic variability to improve heat tolerance in their breeding programmes.
Forage sorghum is an important component of the fodder supply chain in the arid and semi-arid regions of the world because of its high productivity, ability to utilize water efficiently and adaptability to a wide range of climatic conditions. Identification of high-yielding stable genotypes (G) across environments (E) is challenging because of the complex G × E interactions (GEI). In the present study, the performance of 16 forage sorghum genotypes over seven locations across the rainy seasons of 2010 and 2011 was investigated using GGE biplot analysis. Analysis of variance revealed the existence of significant GEI for fodder yield and all eight associated phenotypic traits. Location accounted for a higher proportion of the variation (0·72–0·91), while genotype contributed only 0·06–0·21 of total variation in different traits. Genotype-by-location interactions contributed 0·02–0·13 of total variation. Promising genotypes for fodder yield and each of the associated traits could be identified effectively using a graphical biplot approach. The majority of test locations were highly correlated. A ‘Which-won-where’ study partitioned the test locations into two mega-environments (MEs): ME1 was represented by five locations with COFS 29 as the best genotype, while ME2 had two locations with S 541 as the best genotype. The existence of two MEs suggested a need for location-specific breeding. Genotype-by-trait biplots indicated that improvement for forage yield could be achieved through indirect selection for plant height, leaf number and early vigour.
Growth acceleration or catch-up growth (CUG) in early infancy is a plausible risk factor for later obesity and cardiovascular disease. We postulate that this risk may be mediated by an adverse programming of body composition by CUG in early infancy. The study was aimed at evaluating the association between the pattern of gain in weight and length of term low birth weight (LBW) infants from birth to 6 months, with fat mass percent (FM%) at 6 months. Term healthy singleton LBW infants were enrolled. Baby’s weight and length z-scores were measured at birth and three follow-up visits. Body composition was measured by dual-energy absorptiometry at last visit. A total of 54 babies (28 boys) were enrolled. The mean birth weight and gestation were 2175±180 g and 37.6±0.6 weeks. Follow-up visits were at 1.4±0.0, 3.0±0.3 and 7.2±0.8 months. The proportion of babies who showed CUG [increase in weight for age z-score (∆WAZ)>0.67] from birth to 1.4, 3.0 and 7.2 months was 29.6, 26.4 and 48.5%, respectively. The mean FM% at 7.2 months was 16.6±7.8%. Infants with greater ∆WAZ from birth to 3 and 7.2 months had significantly greater FM% at 7.2 months after adjusting for current age, size and gender. Infants with early CUG (<1.4 months) had higher FM% than infants with no CUG. We conclude that earlier and greater increment in WAZ is positively associated with FM%.
As the need for smaller data storage devices in the market continues to grow, the study of new combinations of self-assembled magnetic nanoparticles/films is greatly needed. In this research, Fe50-Ni50 films were synthesized using a Pulsed Laser Deposition technique. The films were analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and physical properties measurement system (PPMS). Films were deposited from Fe-Ni alloy target (50%-50% composition), deposition was conducted in vacuum, at substrate temperatures varying from liquid nitrogen temperature -196°C to 600°C. The films were annealed in a vacuum chamber at 600°C for 1 hour. The study reveals that the substrate temperature has significant effect on the structure of the films and their magnetic properties. It was shown that additional thermal treatment improved the quality of films in terms of narrow grain size distribution. Magnetic properties were also found to improve significantly after post annealing process.
This paper describes the organometallic synthesis of pure rhenium nanoparticles (Re NPs) and their characterization by a combination of state-of-the art techniques (TEM, HAADF-STEM, EDX, WAXS, EA, FT-IR). The Re NPs synthesis is achieved by reducing the [Re2(C3H5)4] complex in solution under a dihydrogen atmosphere and in the presence of hexadecylamine or polyvinylpyrrolidone as stabilizing agents. The so-obtained Re NPs are monodisperse with a mean size of 1.1 nm (0.3) nm and display a spherical shape with a disordered hcp structure.
The present work addresses the systematic evaluation of the influence of the incorporation of dopant species (Ca+2, Ag+1) on the structural and functional properties of bismuth ferrite (BFO) nanocrystalline powders and films. Pure and doped BFO powders and thin films were synthesized by a modified sol-gel method. The concentration of the doping species varied from 0 up to 7 at %. The development of the host BFO structure was confirmed by XRD analyses of samples annealed at 700°C for one hour in air and nitrogen atmosphere. Thicknesses of films varied between 80 and 200 nm, depending on the concentration of Ca+2 species. Doped BFO exhibited a magnetic behavior that turned from paramagnetic into ferrimagnetic with the increase of Ca+2 concentrations.
Soft lithographic printing techniques can be used to print nanoparticle dispersions with relative ease while allowing for a measureable degree of controllability of printed feature size. In this study, a Polydimethylsiloxane (PDMS) stamp was used to print multi-layered, porous, nanoparticle dispersions of titanium dioxide (TiO2), for use in a dye-sensitized solar cell application. The gelled patterns were then sintered and the surface of the printed sample was chemically analyzed.
X-ray photoelectron spectroscopy (XPS) was used to determine the surface constituents of the printed sample. The presence of a secondary peak feature located approximately 2.8 eV above the high resolution O1s core level binding energy peak was attributed to a contamination layer. Fourier transform infrared spectra (FTIR) of the printed sample revealed the presence of vibrational modes characteristic of the asymmetric bond stretching of silica, located at approximate wavenumbers of 1260 and 1030 cm-1.
Soft lithographic techniques are a viable manufacturing technique in a number of disciplines and sintered nano-oxide dispersions are readily used as reaction centers in a number of technologies. The presence of a residual, bonded silicate contamination layer may preclude the soft lithographic printing of chemically active oxide surfaces.
Due to the rapid advance of the emergence of resistant microorganisms to different antibiotics, there is a need to create new antimicrobial agents. It is possible that Nanotechnology has a great impact in this area since the nanoparticles can improve the antimicrobial effect of the antibiotics. In this study we used three different metal oxides nanoparticles, the MgO, ZnO and CuO. These nanoparticles were selected because their interactions leading to cell death and their optical properties. The aim of this study is to develop new methods that are more effective against resistance bacteria, developing antibacterial agents using different nanoparticles against Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145), and Staphylococcus aureus (ATCC BAA-1026). This study was conducted to evaluate the antibacterial effects of a combination of nanoparticles together with different concentrations of three antibiotics, Gentamicin, Cephalexin and Co-Trimoxazole. The results showed that some nanoparticles are effective to inhibit growth in these microorganisms by increasing the effectiveness of the antibiotic. Therefore, the present study indicates that the combination of the nanoparticles with antibiotics may be applicable as a new antimicrobial agent.
In this contribution, we report the synthesis and characterization of NixFe3-xO4 and CoxFe3-xO4 redox nanomaterials using sol-gel method. These materials will be used to produce solar fuels such as H2 or syngas from H2O and/or CO2 via solar thermochemical cycles (STCs). For the sol-gel synthesis of ferrites, the Ni, Co, Fe precursor salts were dissolved in ethanol and propylene oxide (PO) was added dropwise to the well mixed solution as a gelation agent to achieve gel formation. Freshly synthesized gels were aged, dried, and calcined by heating them to 600°C in air. The calcined powders were characterized by powder x-ray diffractometer (XRD), BET surface area, as well as scanning (SEM) and transmission (TEM) electron microscopy. Their suitability to be used in STCs for the production of solar fuels was assessed by performing several reduction/re-oxidation cycles using a thermogravimetric analyzer (TGA).
SnO2-based varistors are strong candidates to replace the ZnO-based varistors due to ordering fewer additives to improve its electrical behavior as well as by showing similar nonlinear characteristics of ZnO varistors. In this work, SnO2-nanoparticles based-varistors with addition of 1.0 %mol of ZnO and 0.05 %mol of Nb2O5 were synthesized by chemical route. SnO2.ZnO.Nb2O5-films with 5 μm of thickness were obtained by electrophoretic deposition (EPD) of the nanoparticles on Si/Pt substrate from alcoholic suspension of SnO2-based powder. The sintering step was carried out in a microwave oven at 1000 °C for 40 minutes. Then, Cr3+ ions were deposited on the films surface by EPD after the sintering step. Each sample was submitted to different thermal treatments to improve the varistor behavior by diffusion of ions in the samples. The films showed a nonlinear coefficient (α) greater than 9, breakdown voltage (VR) around 60 V, low leakage current (IF ≈ 10-6 A), height potential barrier above 0.5 eV and grain boundary resistivity upward of 107 Ω.cm.
The present work focuses on the synthesis and evaluation of the antimicrobial activity of ZnxMg1-xO solid solutions. ZnxMg1-xO solid solutions were synthesized through the thermal decomposition of ZnMg-precursor synthesized in aqueous and ethanol solutions via a two-steps process. The antimicrobial activity of ZnxMg1-xO solid solution against E. coli was evaluated using the spread plate method in presence of ZnxMg1-xO powder of different contents of Zn species, ‘x’. The powder concentrations evaluated were 500, 1000, and 1500 ppm. Zn0.10Mg0.90O powders exhibited a bacterial growth inhibition between 38% and 100% when the powder concentration increased from 500 up to 1500 ppm, respectively. A decreasing trend was observed for x = 0.30 and above; the corresponding bacterial growth inhibition was 12%, 6%, and 5% when the particles concentration was, respectively, 500, 1000, and 1500 ppm. X-Ray diffraction analyses suggested the incorporation of Zn ions into the MgO lattice for ‘x’ values below 0.10, enhancing the antimicrobial activity; the formation of two isolated oxide phases observed at larger ‘x’ values (e.g. x = 0.30 and x = 0.50 Zn), could explain the detected inhibition of the corresponding antimicrobial activity.
Strontium titanate (SrTiO3) has novel properties, including a large temperature-dependent dielectric constant, and can be doped to make it metallic or even superconducting. The origin of conductivity observed at the SrTiO3/LaAlO3 interface is a topic of intense debate. In the present work, bulk single crystal SrTiO3 samples were heated at 1200°C, with the goal of producing cation vacancies. These thermally treated samples exhibited persistent photoconductivity (PPC) at room temperature. Upon exposure to sub-band-gap light (>2.9 eV), the free-electron density increases by over two orders of magnitude. This enhanced conductivity persists in the dark, at room temperature, for several days with essentially no decay. Light excites an electron from the vacancy to the conduction band, where it remains, due to a large recapture barrier. These observations highlight the importance of defects in determining the electrical properties of oxides and may point toward novel applications.
Ferroelectric epitaxial Pb(Zr,Ti)O3 (PZT) layers were grown by pulsed laser deposition on SrTiO3/GaAs templates fabricated by molecular beam epitaxy. The templates present an excellent structural quality and the SrTiO3/GaAs is abrupt at the atomic scale thanks to surface Ti pre-treatment. The PZT layers contain a- and c- domains, as shown by X-Ray diffraction analyses. Piezoforce microscopy experiments and macroscopic electrical characterizations indicate that PZT is ferroelectric. A relative dielectric permittivity of 164 is extracted from these measurements.
In the present work, we report the synthesis and characterization of NaNbO3 particles obtained by microwave-assisted hydrothermal method from Nb2O5 and NaOH. The synthesis was made at different periods at 180 °C and 300W. The crystallization of NaNbO3 structures produced Na2Nb2O6.H2O in the intermediate phase with fiber-like morphology, and this is associated with the synthesis time. Pure orthorhombic NaNbO3 with cube-like morphology originates after synthesizing for 240 minutes. To verify the remnant polarization of particles, films were obtained by electrophoresis process and sintered at 800°C for 10 minutes in a microwave furnace. The films characterization indicated that films of niobate with fiber-like morphology present remaining polarization, and the morphology of cubes did not show remaining polarization. Considering these results, it can be concluded that the morphology implemented ferroelectric property of NaNbO3.