Oxidative degradation studies of an oxazolidinone-derived antibacterial agent, RWJ416457, in aqueous solutions

The rates of oxidative degradation of a new antibacterial drug, RWJ416457, in aqueous solutions were investigated over the pH-range of 2 to 10. Two oxidative degradates were identified and the influences of pH, buffer concentration, metal ions, metal chelating agents, and temperatures were studied. The pH, metal chelating agents, and metal ions significantly changed the product distribution in addition to the degradation rate. Oxidative degradation is believed to follow a hydrogen abstraction (HAT) pathway. One degradate was the major product under acidic conditions and its predominance is attributed to a resonance-stabilized intermediate. The importance of the resonance structure was diminished under neutral and basic conditions. The product distribution changed and two degradates were formed in equal amounts. The study results guided the formulation development to minimize oxidation.     

The interaction between cytoplasmic dynein and dynactin is required for fast axonal transport

Fast axonal transport is characterized by the bidirectional, microtubule-based movement of membranous organelles. Cytoplasmic dynein is necessary but not sufficient for retrograde transport directed from the synapse to the cell body. Dynactin is a heteromultimeric protein complex, enriched in neurons, that binds to both microtubules and cytoplasmic dynein. To determine whether dynactin is required for retrograde axonal transport, we examined the effects of anti-dynactin antibodies on organelle transport in extruded axoplasm. Treatment of axoplasm with antibodies to the p150(Glued) subunit of dynactin resulted in a significant decrease in the velocity of microtubule-based organelle transport, with many organelles bound along microtubules. We examined the molecular mechanism of the observed inhibition of motility, and we demonstrated that antibodies to p150(Glued) disrupted the binding of cytoplasmic dynein to dynactin and also inhibited the association of cytoplasmic dynein with organelles. In contrast, the anti-p150(Glued) antibodies had no effect on the binding of dynactin to microtubules nor on cytoplasmic dynein-driven microtubule gliding. These results indicate that the interaction between cytoplasmic dynein and the dynactin complex is required for the axonal transport of membrane-bound vesicles and support the hypothesis that dynactin may function as a link between the organelle, the microtubule, and cytoplasmic dynein during vesicle transport.     

Comparative study of natural calcium stilbite and magnesium exchanged stilbite for ethanol sensing

Natural stilbite (Ca-stilbite) zeolites have been collected from the queries near Pashan area, Pune, Maharashtra, India. The calcium ions in the Ca-stilbite structure are partially exchanged by magnesium ions using ion exchange process. The Ca-stilbite and Mg- stilbite samples are characterized by XRD, EDS, FTIR and TG/DTA techniques and are used as the functional materials for the preparation of thick films using screen printing technique. The screen printed films, deposited on glass substrates, are then sintered at 650 °C for proper adhesion to take place. These thick films are used as sensors to test ethanol. The XRD profiles and FTIR spectra reveal that the sensor material is a stilbite zeolite. EDS data shows that the magnesium ions are exchanged in the stilbite structure. TG/DTA study shows the thermal behavior of the samples wherein the structural breakdown occurs at 520 °C and weight loss due to desorption of water molecules can be revealed by exo & endo peaks. Ethanol sensing studies show that both the Ca-stilbite and Mg-stilbite films are sensitive to ethanol. In case of Mg-stilbite films, the operating temperature and ethanol response are found to be dependent on magnesium concentration. Lower the magnesium concentration lower is the operating temperature and higher is the ethanol sensitivity. Mg-stilbite films with specific concentration (0.05 M) shows the consistent ethanol sensing performance in comparison to Ca-stilbite film wherein response to ethanol decreases after repetitive use. The study reveals that Mg-stilbite thick film (0.05 M) is stable ethanol sensor which can be operated at 65 °C with reproducible characteristics.     

Atomistic visualization: Space–time multiresolution integration of data analysis and rendering

Time-varying three-dimensional scattered data representing snapshots of atomic configurations produced by molecular dynamics simulations are not illuminating by themselves; gaining insight into them poses a tremendous challenge. In order to take the advantage of maximal information offered by these simulations, we have proposed an efficient scheme, which integrates various analysis and rendering tasks together in order to support interactive visualization of the data at space–time multiresolution. Additional data produced by various analytical techniques on the fly represent the atomic system under consideration at diverse length- (e.g., nearest neighbor, next-nearest neighbor or beyond) and time- (e.g., instantaneous, finite intervals or overall averages) scales. In particular, the radial distribution functions, coordination environments, clusters and rings are computed and visualized to understand the structural behavior whereas a variety of displacement data and covariance matrices are explored to understand the dynamical behavior. While the spatial distributions of atoms need to be reproduced correctly during rendering, we take the advantage of high flexibility in rendering other attributes because of the lack of their direct physical relevance. A combination of different techniques including animation, color maps, pathlines, different types of glyphs, and graphics hardware accelerated approach is exploited to render the original and extracted data. First-principles molecular dynamics simulation data for liquid systems are used to justify the effectiveness and usefulness of the proposed scheme.     

Cost of unserved power in Karnataka,India

This paper proposes an empirical analysis concerning the cost of unserved energy (CUE) or value of lost load in agriculture and industrial sectors and provides insights that can provide useful inputs in designing effective policies for the power sector. About 500 manufacturing units and 900 farmers were surveyed in the south Indian state of Karnataka using a two-stage random sampling to provide interval estimates of CUE for the industrial and agricultural consumers. The results from the survey help in providing guidance on consumer perceptions and their willingness to pay different or higher tariffs. The estimated economic loss due to power outage in the agriculture sector varies from 1.9% to 3.6% of total State Domestic Product (SDP), i.e., Rs 950 billion at 1999/2000 prices, while in industry, the economic loss varies between 0.04% and 0.17% of total SDP depending upon the size of industry during the study period in 1999.     

Capacity reserve assessment using system well-being analysis

Deterministic methods are widely used in operating reserve assessment and in small isolated power system capacity planning. These approaches do not normally include any explicit recognition of system risk and do not provide comparable risks for systems of different size or composition. Many large power systems, therefore, use probabilistic methods for generation adequacy evaluation. The reluctance to utilize the existing probabilistic techniques in both large and small systems dictates a need to create a bridge between the two different approaches. This paper presents a new probabilistic method designated as `system well-being analysis', which incorporates the accepted deterministic criteria in the definition of `healthy' and `marginal' power system states. This paper illustrates methodologies to evaluate the system well-being indices of practical systems and describes how they can be used in the assessment of power system capacity reserves     

Equivalent Viscosity of Plasma and Plasma Substitutes in Oscillatory Flow

Womersley's theory of oscillatory flow has been used to determine the equivalent viscosity (analogous to the apparent viscosity under steady flow conditions) of plasma and plasma substitutes (dextrans) of various molecular weights in rigid cylindrical tubes of radii ranging from 0.0304 to 0.162 cm. It is shown that the equivalent viscosity of dextran solutions is radius independent and is higher than that of plasma, at all frequencies. The continuum theory of suspensions, developed by Kline and Allen, is shown to be in good agreement with these findings.     

Multislice tomographic imaging and analysis of human breast-equivalent phantoms and biological tissues

A laser transillumination tomographic system, consisting of electrical, optical, mechanical, and software components, to obtain multislice images of tissue-equivalent breast phantoms and biological tissues, is developed. The tissue-equivalent phantoms are prepared from paraffin wax mixed with wax color pigments by matching their surface backscattered profiles as measured by multiprobe laser reflectometer, with that of respective tissues. The optical parameters of these phantoms are determined by matching their reflectance profiles with that as obtained by Monte Carlo simulation of optical scattering. For multislice tomographic analysis conical breast phantoms of height 80.0 mm and 80.0 mm base diameter with inclusions of different optical properties and dimensions are developed. The resolution of the inclusions in the tomograms depends on their sizes and optical parameters. The minimum size of the inclusion as detected by this procedure in a slice of diameter 50.0 mm is 3.0 mm. The structural variation as observed in the tomograms of phantoms of combination of biological tissues indicates its possible applications in detecting the abnormalities developing in human healthy soft tissues.     

Characterization and imaging of compositional variation in tissues

The diffuse surface reflectance profiles of the goat's isolated heart, spleen, and adipose tissues by multiprobe laser reflectometer are measured. The normalized backscattered intensity values for adipose, heart, and spleen tissues at source-detector separation 0.2 cm, are 0.060, 0.021, and 0.003, respectively. The optical parameters of these tissues are determined by the best fit (chi2(0.99)) of their spatial profiles with that as obtained by Monte Carlo simulation by iterative procedure. As the optical parameters of these vary over a wide range, adipose and spleen tissues are treated as inhomogeneity of diameter 0.1, 0.2, or 0.3 cm, and placed inside the control (heart) tissue at different depths. Anisotropic simulation of light backscattering or photon depth distribution is significantly different for various tissues. The surface intensity profiles vary depending on the changes in tissue composition. From the horizontal scans of the subtracted images, the photon backscattering simulated images of control and combination of tissues are obtained. By analysis of peak intensity and full-width at half maximum, the type, location, and size of the tissue compositional variation are determined.     

Dynamic small world particle swarm optimizer for function optimization

Performance of particle swarm optimization technique is highly influenced by the population topology. It determines the way in which particles communicate and share information within a swarm. If path length is too small, it implies that a particle communicates with other particles in its close proximity leading to exploitation. On the contrary, if path length is large then the particle interacts with other remote particles leading to exploration. There needs to be a balance between exploration and exploitation and Small world network fits to this need of ours. In this paper, dynamic small world network has been proposed with the objective to have a balanced trade-off between exploration and exploitation. In order to make learning process dynamic linearly decreasing inertia weight has been employed. Experimental study is performed on a set of 23 test functions using different performance evaluation measures. Results obtained are compared with other state of the art techniques demonstrating the effectiveness of the proposed approach.