Gate leakage current reduction in IP3 SRAM cells at 45 nm CMOS technology for multimedia applications

We have presented an analysis of the gate leakage current of the IP3 static random access memory (SRAM) cell structure when the cell is in idle mode (performs no data read/write operations) and active mode (performs data read/write operations), along with the requirements for the overall standby leakage power, active write and read powers. A comparison has been drawn with existing SRAM cell structures, the conventional 6T, PP, P4 and P3 cells. At the supply voltage, V_DD = 0.8 V, a reduction of 98%, 99%, 92% and 94% is observed in the gate leakage current in comparison with the 6T, PP, P4 and P3 SRAM cells, respectively, while at V_DD = 0.7 V, it is 97%, 98%, 87% and 84%. A significant reduction is also observed in the overall standby leakage power by 56%, the active write power by 44% and the active read power by 99%, compared with the conventional 6T SRAM cell at V_DD = 0.8 V, with no loss in cell stability and performance with a small area penalty. The simulation environment used for this work is 45 nm deep sub-micron complementary metal oxide semiconductor (CMOS) technology, t_ox = 2.4 nm, V_thn = 0.22 V, V_thp = 0.224 V, V_DD = 0.7 V and 0.8 V, at T = 300 K.     

Increasing the effective interfacial area in plastic packed absorption columns.

Effective interfacial areas for gas absorption were measured at various irrigation rates for Raschig rings made of a ceramic (industrial porcelain) and of various plastics. The plastics used were polyethylene and polypropylene having very low wettabilities with water. The surface of some of the plastic packings was covered with a hydrophilic layer. The absorption of pure oxygen by a sodium sulphite solution containing cobalt catalyst was used for the measurement of effective interfacial area. It has been found that the effective interfacial area of plastic packings was about 40 per cent of that of geometrically similar ceramic packings. The effective interfacial area of the plastic packings was increased about 2·5 times by application of the hydrophilic layer. Thus, the wetted surface areas of plastic packings with hydrophilic surface and of ceramic packings are practically the same.     

Negative electrodes for nickel-cadmium accumulators: their properties as determined by impregnation procedure

Sintered negative electrodes for nickel-cadmium secondary cells were studied. Model electrodes prepared by means of three different impregnation methods were evaluated. It was demonstrated that the impregnation procedure may affect properties of active mass and the service life of electrodes in a significant way.     

Polymer derived ceramic materials from Si,B and MoSiB filler-loaded perhydropolysilazane precursor for oxidation protection

Silica-based coating systems were developed using polymer derived ceramics (PDCs) technology. Ceramic composites on the base of a SiO₂ and SiNO matrix and homogeneously distributed Mo₅SiB₂, SiB₆, Si and B fillers were manufactured. The coating systems have low porosity and provide a high oxidation resistance up to 100 h at 800 °C and 1100 °C in air. The influence of temperature and atmosphere of pyrolysis on the polymer precursor, the volume fraction of filler materials on the chemical composition of compacts as well as their high-temperature oxidation protection was investigated.     

Self-standing nanoparticle membranes and capsules

We perform coarse-grained molecular dynamics simulations of self-standing nanoparticle membranes observed in recent experiments (K. E. Mueggenburg et al., Nat. Mater., 2007, 6, 656). In order to make our simulations feasible, we model 2-3 times smaller gold nanoparticles (core radius of r(core) ≈ 0.8 nm) covered with alkanethiol ligands (length of l(ligand) ≈ 0.5-2.6 nm). We study the structure, stability, and mechanical properties of these membranes and show that these characteristics are controlled by the ratio of R(LC) = l(ligand)/r(core). For R(LC) ≈ 0.6, the ligated nanoparticles form well ordered monolayers with hexagonal packing, in agreement with the experiments (R(LC) ≈ 0.44). For R(LC) ≈ 1.6, the nanoparticles form less organized multilayers, which are more stable and flexible. We show that these membranes could potentially form stable capsules for molecular storage and delivery.     

Antifungal activity of denture soft lining material modified by silver nanoparticles-a pilot study

Soft liner materials in oral cavity environments are easily colonized both by fungi and dental plaque. These factors are the cause of mucosal infections. The microorganism that most frequently colonizes soft liner materials is Candida albicans. Colonization occurs on the surface of materials and within materials. A solution to this problem might involve modification of soft liner materials with silver nanoparticles (AgNPs). In this article, we present results showing the antifungal efficacy of silicone soft lining materials modified with AgNPs. The modification process was conducted by dissolving both material components (base and catalyst) in a colloidal solution of AgNPs and evaporating the solvent. Composites with various AgNP concentrations (10, 20, 40, 80, 120 and 200 ppm) were examined. The in vitro antifungal efficacy (AFE) of composite samples was 16.3% to 52.5%.     

Synthesis and characterization of magnetic nanocomposites of fullerene‐containing polyurethane films for microwave applications

Novel nanocomposites of barium hexaferrite‐ and fullerene‐containing polyurethane were synthesized and characterized by scanning electron microscopy, transmission electron microscopy, X‐ray diffractometry, and energy‐dispersive X‐ray diffraction. The nanoparticles showed good dispersion in the polyurethane matrix. Their thermal, mechanical, and electromagnetic absorbance properties were studied. The complex permeability and permittivity were measured in the frequency range of 8.2–12.4 GHz. The maximum reflection loss of the nanocomposites was found to increase with increasing the ferrite content from 1% to 5%, with maximum value of −7.5 dB at only 5% composition. The incorporation of nanofiller not only imparts mechanical strength to the nanocomposite but also shows good radar‐absorbing properties at only 5% filler concentration. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Hen Egg White Lysozyme Catalyzed Efficient Synthesis of 3-Indolyl-3-hydroxy Oxindole in Aqueous Ethanol

A green synthesis of 3-indolyl-3-hydroxy oxindoles was reported using hen egg white lysozyme (HEWL) in an aqueous ethanol. The HEWL promotes this reaction efficiently from various isatins and indoles under mild reaction conditions with yields up to 98% bearing good adaptability to varied substrates in the reaction. This conversion has provided a new strategy to synthesize 3-indolyl-3-hydroxy oxindole derivatives employing biocatalytic promiscuity of less explored lysozyme. Based on the experimental studies, the plausible reaction mechanism is proposed.

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Photocaged Hoechst Enables Subnuclear Visualization and Cell Selective Staining of DNA in vivo

Selective targeting of DNA by means of fluorescent labeling has become a mainstay in the life sciences. While genetic engineering serves as a powerful technique and allows the visualization of nucleic acid by using DNA-targeting fluorescent fusion proteins in a cell-type- and subcellular-specific manner, it relies on the introduction of foreign genes. On the other hand, DNA-binding small fluorescent molecules can be used without genetic engineering, but they are not spatially restricted. Herein, we report a photocaged version of the DNA dye Hoechst33342 (pcHoechst), which can be uncaged by using UV to blue light for the selective staining of chromosomal DNA in subnuclear regions of live cells. Expanding its application to a vertebrate model organism, we demonstrate uncaging in epithelial cells and short-term cell tracking in vivo in zebrafish. We envision pcHoechst as a valuable tool for targeting and interrogating DNA with precise spatiotemporal resolution in living cells and wild-type organisms.