Characterization and Genomic Analysis of Escherichia coli O157:H7 Phage UAE_MI-01 Isolated from Birds

Verotoxin-producing Escherichia coli O157:H7 is responsible for the majority of foodborne outbreaks worldwide and may lead to death. Bacteriophages are natural killers of bacteria. All previously reported E. coli O157:H7 phages were isolated from ruminants or swine. Here, we report for the first time a phage isolated from bird feces in the United Arab Emirates (UAE), designated as UAE_MI-01, indicating birds as a good source of phages. Thus, phages could be a tool for predicting the presence of the host bacteria in an animal or the environment. UAE_MI-01 was found to be a lytic phage that was stable at wide ranges of pH, temperature, and chemical disinfectants, and with a burst size of almost 100 plaque-forming units per host cell after a latent period of 20 min and an adsorption rate constant (K) of 1.25 × 10⁻⁷ mL min⁻¹. The phage genome was found to be 44,281 bp long with an average GC content of 54.7%. The presence of the phage indicates the presence of the host cell E. coli O157:H7 in wild birds. Therefore, other birds, mainly poultry, could be also investigated for the presence of this pathogenic bacterium. To the best of our knowledge, this is the first report of an E. coli O157:H7 bacteriophage isolated from a bird.     

Synthesis,characterization and thermal degradation of dual temperature‐ and pH‐sensitive RAFT‐made copolymers of N,N‐(dimethylamino)ethyl methacrylate and methyl methacrylate

Poly{[(N,N‐(dimethylamino)ethyl methacrylate]‐co‐(methyl methacrylate)} copolymers of various compositions were synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization at 70 °C in N,N‐dimethylformamide. The polymer molecular weights and molecular weight distributions were obtained from size exclusion chromatography, and they indicated the controlled nature of the RAFT polymerizations; the polydispersity indices are in the range 1.1–1.3. The reactivity ratios of N,N‐(dimethylamino)ethyl methacrylate (DMAEMA) and methyl methacrylate (MMA) (r_DMAEMA = 0.925 and r_MMA = 0.854) were computed by the extended Kelen–Tüdös method at high conversions, using compositions obtained from ¹H NMR. The pH‐ and temperature‐sensitive behaviour were studied in aqueous solution to confirm dual responsiveness of these copolymers. The thermal properties of the copolymers with various compositions were investigated by differential scanning calorimetry and thermogravimetric analysis. The kinetics of thermal degradation were determined by Friedmann and Chang techniques to evaluate various parameters such as the activation energy, the order and the frequency factor. © 2012 Society of Chemical Industry     

Synthesis and characterization of nanocrystalline ScSZ electrolyte for SOFCs

Sc₂O₃ stabilized zirconia (ScSZ) was processed by combustion synthesis. X-ray diffraction was carried for analyzing the phase and crystallinity of the processed powder. The results indicate the effectiveness of the combustion synthesis process to produce nanocrystalline ScSZ from the precursor salts without any intermediate calcination step. Comparison with the X-ray diffraction pattern of a commercial 8YSZ sample showed that the process is also effective in producing the desired cubic fluorite phase. The powder was compacted and sintered to produce a dense electrolyte pellet. The sintering temperature was found to be considerably lower compared to conventional microcrystalline zirconia ceramics. The electrical conductivity of the ScSZ electrolyte was found to be higher compared to 8YSZ processed under same conditions. The Arrhenius plot of conductivity yielded two activation energies corresponding to low and high temperature regions. The activation energy of the 10ScSz electrolyte was found to be considerably lower than the 8YSZ sample.     

Rapid and facile synthesis of Ti-MCM-48 mesoporous material and the photocatalytic performance for hydrogen evolution

A rapid and facile method was used to synthesize high quality titanium containing cubic MCM-48 mesoporous materials at room temperature. Four kinds of titanium containing MCM-48 mesoporous materials were prepared by addition of the titanium precursor at different stages during the formation of MCM-48 gel. The mesoporous structure and the light absorption characteristics of Ti-MCM-48 were studied by X-ray diffraction (XRD), diffuse reflectance spectra (DRS), and nitrogen isotherm studies. The photocatalytic activities of these heterogeneous Ti-MCM-48 catalysts were tested for photocatalytic hydrogen evolution from methanol–water mixture under UV irradiation. High activity was achieved in the absence of platinum cocatalyst, which is usually indispensable to TiO₂ photocatalyst for hydrogen evolution.     

A review on methodology of artificial roughness used in duct of solar air heaters

In order to enhance rate of heat transfer to flowing air in the duct of a solar air heater, artificially roughened surface of absorber plate is considered to be an effective technique. Investigators reported various roughness geometries in literature for studying heat transfer and friction characteristics of an artificially roughened duct of solar air heaters. In the present paper an attempt has been made to categorize and review the reported roughness geometries used for creating artificial roughness. Heat transfer coefficient and friction factor correlations developed by various investigators for roughened ducts of solar air heaters have also been reported in the present paper.     

Experimental performance study of cryogenic turboexpander by using aerodynamic thrust bearing

An indigenous programme on design and development of a small high speed cryogenic turboexpander has been taken up at NIT, Rourkela. This paper aims at the development of a small high speed cryogenic turboexpander in Indian condition by using aerodynamic thrust bearings. Attention has been paid to the study of the performance of turboexpander and the effect of stability on the vibration of bearings. Series of tests were conducted to confirm the findings. The maximum rotational speed obtained was 200,000 rpm and a temperature drop of 30 °C. The outcome may help the designers, researchers and manufacturer of these components.     

Real-time glucose sensing by surface-enhanced Raman spectroscopy in bovine plasma facilitated by a mixed decanethiol/mercaptohexanol partition layer

A new, mixed decanethiol (DT)/mercaptohexanol (MH) partition layer with dramatically improved properties has been developed for glucose sensing by surface-enhanced Raman spectroscopy. This work represents significant progress toward our long-term goal of a minimally invasive, continuous, reusable glucose sensor. The DT/MH-functionalized surface has greater temporal stability, demonstrates rapid, reversible partitioning and departitioning, and is simpler to control compared to the tri(ethylene glycol) monolayer used previously. The data herein show that this DT/MH-functionalized surface is stable for at least 10 days in bovine plasma. Reversibility is demonstrated by exposing the sensor alternately to 0 and 100 mM aqueous glucose solutions (pH approximately 7). The difference spectra show that complete partitioning and departitioning occur. Furthermore, physiological levels of glucose in two complex media were quantified using multivariate analysis. In the first system, the sensor is exposed to a solution consisting of water with 1 mM lactate and 2.5 mM urea. The root-mean-squared error of prediction (RMSEP) is 92.17 mg/dL (5.12 mM) with 87% of the validation points falling within the A and B range of the Clarke error grid. In the second, more complex system, glucose is measured in the presence of bovine plasma. The RMSEP is 83.16 mg/dL (4.62 mM) with 85% of the validation points falling within the A and B range of the Clarke error grid. Finally, to evaluate the real-time response of the sensor, the 1/e time constant for glucose partitioning and departitioning in the bovine plasma environment was calculated. The time constant is 28 s for partitioning and 25 s for departitioning, indicating the rapid interaction between the SAM and glucose that is essential for continuous sensing.     

PRODUCTION OF HYDROCORTISONE MICRO- AND NANO-PARTICLES USING SUPERCRITICAL ANTI-SOLVENT WITH ENHANCED MASS TRANSFER

Supercritical anti-solvent precipitation with enhanced mass transfer (SAS-EM) is used for the formation of particles of hydrocortisone (HC), an anti-inflammatory drug. This technique is similar to the supercritical anti-solvent process but uses a reflecting horn surface that vibrates at 20 kHz frequency, which enhances the mass transfer of the solvent to supercritical fluid anti-solvent, reducing the growth of the particles. Controllable sizes and morphologies of HC particles are obtained using the SAS-EM process. At a power supply of 0 watts (to ultrasonic transducer), HC fibers of an average length of ∼81 μm and an average diameter of ∼6 μm are obtained. Upon increasing the power supply to 120 watts, which enhances mass transfer, particles of average size as low as 180 nm are obtained. Intermediate particle size and morphology are easily obtained by adjusting the power supply to the desired intermediate value. The obtained powder is free of impurities and is mostly amorphous.     

Reduction of the decision table: A rough approach

In this article, we generalize Pawlak's rough approach for simplifying the decision table in an information system. We consider an information system where attribute values are not always quantitative, but are rather subjective, having vague or imprecise meanings. Some objects may have attribute values that are almost identical; that is, they cannot be distinguished clearly by the attributes. This observation is analyzed here being based on fuzzy proximity relations on different domain of attributes. Finally we find out the minimal solution of the table. © 2004 Wiley Periodicals, Inc. Int J Int Syst 19: 1143–1150, 2004.     

Encoding scheme for data storage and retrieval on DNA computers

There has been exponential growth in the amount of data being generated on a daily basis. Such a huge amount of data creates a need for efficient data storage techniques. Due to the limitations of existing storage media, new storage solutions have always been of interest. There have been recent developments in order to efficiently use synthetic deoxyribonucleic acid (DNA) for information storage. DNA storage has attracted researchers because of its extremely high data storage density, about 1 exabyte/mm³ and long life under easily achievable conditions. This work presents an encoding scheme for DNA‐based data storage system with controllable redundancy and reliability, the authors have also talked about the feasibility of the proposed method. The authors have also analysed the proposed algorithm for time and space complexity. The proposed encoding scheme tries to minimise the bases per letter ratio while controlling the redundancy. They have experimented with three different types of data with a value of redundancy as 0.75. In the randomised simulation setup, it was observed that the proposed algorithm was able to correctly retrieve the stored data in our experiments about 94% of the time. In the situation, where redundancy was increased to 1, the authors were able to retrieve all the information correctly in the proposed experiments.Inspec keywords: DNA, computational complexity, digital storage, storage media, biocomputingOther keywords: encoding scheme, DNA computers, exponential growth, storage media, synthetic deoxyribonucleic acid, information storage, extremely high data storage density, DNA‐based data storage system, controllable redundancy, stored data