Identification and screening of antimalarial phytochemical reservoir from northeastern Indian plants to develop PfRIO-2 kinase inhibitor

Every year, malaria caused by Plasmodium falciparum leads to 1 million deaths. Disease condition is alarming due to acquired resistance in parasite against antimalarial drugs in circulation. It brings the necessity to design novel inhibitors against newly identified drug targets. RIO-2 kinase regulates ribosome biogenesis and represents a promising drug target. Northeastern region of India is a biodiversity hub with a rich source of medicinal plants. Medicinal plants represent a source of phytochemical library to be screened to develop an inhibitor against the PfRIO-2 kinase. In current report, we selected plants with known antimalarial activity and performed in silico screening with phytochemicals against PfRIO-2 as a target. The majority of antimalarial phytochemicals docked very well into the ATP binding pocket of the PfRIO-2 kinase. A competition assay with substrate ATP indicates that a total of 5 phytochemicals, rutin, bebeerines, isochondrodendrine, nimbin and punicalagin, share similar interactions with protein residues within the ATP binding pocket and have potential to inhibit ATP binding. A significant relationship was found between docking energy and experimentally determined antimalarial values of rutin, bebeerines, isochondrodendrine, nimbin and punicalagin (R ² = 0.91, p < 0.001). Docking and virtual screening has identified lead phytochemicals, namely rutin, bebeerines, isochondrodendrine, nimbin and punicalagin, as a potent PfRIO-2 inhibitor, but cannot replace experimental verification. We are hopeful that the current study will help to understand the antimalarial action of the phytochemicals and design effective chemotherapy against malaria.     

On the effect of channel spacing,launch power,and regenerator placement on the design of mixed-line-rate optical networks

Due to the increasing heterogeneity and the growing volume of traffic, telecom backbone networks are going through significant innovations. Wavelength-division multiplexed (WDM) optical networks can now cost-effectively support the growing heterogeneity of traffic demands by having mixed line rates (MLR) over different wavelength channels.The coexistence of wavelength channels with different line rates, e.g., 10/40/100 Gbps, in the same fiber brings up various design issues: in this study, we focus on (1) choice of channel spacing; (2) choice of launch power; and (3) regenerator placement. Channel spacing affects the signal quality in terms of bit-error rate (BER), and hence affects the maximum reach of lightpaths, which is a function of line rates. Various approaches to set an opportunistic width of the channel spacing can be considered, viz., (i) uniform fixed channel spacing specified by the ITU-T grid (typically 50 GHz); (ii) different channel spacing for different line rates; or (iii) optimal value of channel spacing for all line rates that leads to minimum cost.The launch optical power of a signal is another important parameter that affects the network cost. Adjacent channels on different line rates, especially 10 Gbps and 100 Gbps, may exhibit serious degradation of signal quality and optical reach for both the channels due to cross-phase modulation (XPM) between them. Launch power plays a role in such a scenario as it governs the BER by affecting both the signal power and the noise power due to XPM. Moreover, intelligent choice of launch powers on different line rates can significantly reduce the number of regenerators required in the network. The tradeoff between placement of regenerators and choice of launch power is an important problem to address for MLR network design.In this work, we investigate the effects of channel spacing and launch optical power by evaluating the cost of a MLR network for different values of these parameters. We also study the interplay between regenerator placement and launch power. Our results show that (a) it is possible to identify optimal values of channel spacing for a minimum-cost MLR network design, and (b) controlling the power of 10 Gbps and 100 Gbps channels shows maximum sensitivity to the network cost.     

Optical Network Design With Mixed Line Rates and Multiple Modulation Formats

With the growth of traffic volume and the emergence of various new applications, future telecom networks are expected to be increasingly heterogeneous with respect to applications supported and underlying technologies employed. To address this heterogeneity, it may be most cost effective to set up different lightpaths at different bit rates in such a backbone telecom mesh network employing optical wavelength-division multiplexing. This approach can be cost effective because low-bit-rate services will need less grooming (i.e., less multiplexing with other low-bit-rate services onto high-capacity wavelengths), while a high-bit-rate service can be accommodated directly on a wavelength itself. Optical networks with mixed line rates (MLRs), e.g., 10/40/100 Gb/s over different wavelength channels, are a new networking paradigm. The unregenerated reach of a lightpath depends on its line rate. So, the assignment of a line rate to a lightpath is a tradeoff between its capacity and transparent reach. Thus, based on their signal-quality constraints (threshold bit error rate), intelligent assignment of line rates to lightpaths can minimize the need for signal regeneration. This constraint on the transparent reach based on threshold signal quality can be relaxed by employing more advanced modulation formats, but with more investment. We propose a design method for MLR optical networks with transceivers employing different modulation formats. Our results demonstrate the tradeoff between a transceiver's cost and its optical reach in overall network design.      

The Influence of Precipitation of Alpha2 on Properties and Microstructure in TIMETAL 6-4

Samples of Hot Isostatically Pressed (HIPped) powder of TIMETAL 6-4 (Ti-6Al-4V, compositions in wt pct unless indicated), which was HIPped at 1203 K (930 °C), and of forged bar stock, which was slowly cooled from above the beta transus, were both subsequently held at 773 K (500 °C) for times up to 5 weeks and analyzed using scanning and transmission electron microscopy and atom probe analysis. It has been shown that in the samples aged for 5 weeks at 773 K (500 °C), there is a high density of alpha2 (α₂, an ordered phase based on the composition Ti₃Al) precipitates, which are typically 5 nm in size, and a significantly smaller density was present in the slowly cooled samples. The fatigue and tensile properties of samples aged for 5 weeks at 773 K (500 °C) have been compared with those of the HIPped powder and of the forged samples which were slowly cooled from just above the transus, and although no significant difference was found between the fatigue properties, the tensile strength of the aged samples was 5 pct higher than that of the as-HIPped and slowly cooled forged samples. The ductility of the forged samples did not decrease after aging at 773 K (500 °C) despite the strength increase. Transmission electron microscopy has been used to assess the nature of dislocations generated during tensile and fatigue deformation and it has been found that not just is planar slip observed, but dislocation pairs are not uncommon in samples aged at 773 K (500 °C) and some are seen in slowly cooled Ti6Al4V.     

Low-temperature and scalable complementary thin-film technology based on solution-processed metal oxide n-TFTs and pentacene p-TFTs

In this work, a completely scalable integration process is presented for organic–inorganic complementary logic, based on low-temperature spin-coated n-type metal oxide TFTs and thermally evaporated p-type pentacene TFTs. Both transistor types are photolithographically processed side-by-side, without the use of any shadow mask. High performance n-type metal oxide TFTs, post-annealed at a maximum temperature of only 250 °C, exhibit saturation mobilities exceeding 2 cm²/(V s), subthreshold swing as low as 0.19 V/decade and I_on/I_off ratios beyond 10⁷ after integration with p-type pentacene TFTs. Using this hybrid complementary technology, 5-stage and 19-stage ring-oscillators are demonstrated, operating at supply voltages as low as 2.5 V. The ring-oscillators oscillate at a frequency of more than 110 kHz, corresponding to stage delays as low as 0.74 μs, at a supply bias of 20 V.     

HDPE‐Fly Ash/Nano Fly Ash Composites

Fly ash (FA) based polymer composites are assuming increasing importance because of its potentiality, fine particle size and plenty availability of FA. FA is mainly a mixture of inorganic metal oxides such as SiO₂, Al₂O₃, Fe₂O₃, CaO, MgO, Na₂O, TiO₂, and so forth. This article highlights the results of the various modifications onto the HDPE‐FA/nano structured FA (NFA) composites. When FA and NFA are melt blended with HDPE it gives rise to improved flexural properties only. Further modifications, that is, Maleic anhydride (MA) grafting of the matrix, electron beam irradiation of the composite and irradiation of the FA/NFA studied separately to find their impact on the detail properties of the composite. Of the three modifications implemented the electron beam irradiation of HDPE‐FA/NFA composite yielded excellent physico‐mechanical, thermal and dynamic mechanical properties. Fracture surface analysis of the HDPE, unmodified and modified FA/NFA composites studied employing SEM correlated well with the physico‐mechanical properties. The results prove that FA is valuable reinforcing filler for HDPE and its size reduction to nano level is a more effective criterion for its future use. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4558–4567, 2013     

Mechanisms related to different generations of γ′ precipitation during continuous cooling of a nickel base superalloy

This paper focuses on developing a mechanistic understanding of the process of multiple nucleation bursts leading to the formation of multiple generations (or populations) of γ′ precipitates with different size distributions, during the continuous cooling of a commercially used nickel base superalloy. This mechanistic understanding has been developed based on a number of critical experimental results: direct observation of the multiple nucleation bursts during in situ X-ray diffraction studies in the synchrotron, characterization of the size distributions associated with the different populations of γ′ precipitates by coupling multiple imaging techniques at the appropriate length scale and detailed compositional analysis of the γ′ precipitates as well as the γ matrix using atom probe tomography. These analyses reveal that while local compositional equilibrium appears to have been achieved near the γ′/γ interface for the first generation of precipitates, a non-equilibrium long range diffusion profile in the γ matrix is retained during the process of continuous cooling, which is largely responsible for the subsequent nucleation bursts at larger undercooling (or lower temperatures), leading to second and third generations of precipitates. Additionally, since these subsequent generations of precipitates are formed at larger undercoolings, they are typically finer in size scale, exhibit far-from equilibrium compositions and also have very diffuse γ′/γ interfaces, indicating a non-classical precipitation mechanism associated with their formation.     

Air-gap formation during IMD deposition to lower interconnectcapacitance

The use of air-gaps between interconnect metal lines to reduce interconnect capacitance has been explored. Simulations were performed to determine the reduction in capacitance obtainable using air-gaps. The formation of air-gaps in the isolation oxide between metal lines was simulated using Stanford Profile Emulator for Etching and Deposition in IC Engineering (SPEEDIE). The capacitance of the SPEEDIE profiles was then extracted using Raphael (an electrical analysis simulator from TMA). The feasibility of air-gaps was also demonstrated experimentally. Fabricated air-gap structures exhibited a 40% reduction in capacitance when compared to a HDP-CVD oxide gap-fill process with K=4.1. Additionally, the air-gap structures did not exhibit any appreciable leakage current