Different expression patterns of MMP-2 and MMP-9 in breast cancer

The role of nitric oxide (NO) in activation of cGMP is well established. It has been proposed that the ratio of cAMP to cGMP may be important in the regulation of preimplantation embryonic growth and differentiation. Therefore, we determined the ability of murine preimplantation embryos to produce NO. In addition, NO as an endogenous smooth muscle relaxant and vasodilator is a candidate for involvement in embryo implantation because this process requires increased vascular permeability and uterine quiescence at the sites of blastocyst apposition. Nitrite assays, an indirect measure of NO production, indicate that preimplantation murine embryos produce NO. This production was reversibly inhibited by culture of embryos in medium containing a nonspecific NO synthase (NOS) inhibitor (NG-nitro-L-arginine). Additionally, inhibition of normal development was observed in embryos cultured with NOS inhibitor. NO levels increased in culture medium when ovariectomized progesterone-treated animals were exposed to estrogen for 1 h in utero. Such hormonal treatment induces implantation. These data indicate that NO levels are regulated by estrogen and may be important in regulation of implantation. In addition, these data demonstrate for the first time that NO production appears to be required for normal embryonic development.     

The impact of NMOSFET hot-carrier degradation on CMOS analogsubcircuit performance

This study presents some of the first experimental data on the impact of NMOSFET hot-carrier-induced degradation on CMOS analog subcircuit performance. Because of circuit design requirements, most NMOSFET's used for analog applications are biased in the saturation region with a low gate-to-source voltage. Under such operating conditions, in addition to interface states, significant numbers of hole traps are also generated inside the gate oxide. Because acceptor-type interface states are mostly unoccupied in the saturation region, hole traps are found to have a much more significant impact on analog NMOSFET device performance. The hot-carrier-induced degradation of analog subcircuit performance is also found to be quite sensitive to the particular circuit design and operating conditions. Circuit performance and reliability tradeoffs are examined     

Load-carrying capacities of cold-formed steel cut stub columns with lipped C-section

Cutting roll-formed steel lipped C-sections may produce different extent of cross section distortion along the lengths of the sections and may lead to additional initial geometric imperfections. Ten stub columns cut from two different sections were tested under axial compression. Flanges of the stub columns experienced distortional mode of failure, whereas the webs showed signs of local buckling failures. Ultimate compressive strengths obtained from the test results were 75–77% of the strengths estimated based on BS5950:Part 5. This indicates that geometric imperfections caused by cutting may significantly reduce the ultimate strength of stub columns.     

Four-wave mixing of incoherent light in a dispersion-shifted fiberusing a spectrum-sliced fiber amplifier light source

We investigate the FWM efficiency of incoherent light in a dispersion-shifted fiber (DSF) using a spectrum-sliced fiber amplifier light source. A theoretical model is provided to describe the FWM mechanism of incoherent light. The FWM efficiencies of coherent and incoherent light are compared theoretically and experimentally. Unlike the FWM of coherent light, the FWM signals of incoherent light are mostly generated by nondegenerate FWM regardless of the number of input signals. Thus, when two input signals are mixed, incoherent light has about 6 dB higher mixing efficiency than coherent light due to the difference in their degeneracy factor     

Phonon Dispersion Measurements of YBa2Cu3O6.15 and YBa2Cu3O6.95 by Time-of-Flight Neutron Spectroscopy

We measured the phonon dispersions of YBa₂Cu₃O_6.15 and YBa₂Cu₃O_6.95 by time-of-flight inelastic neutron scattering. The in-plane bond-stretching modes in the metallic phase showed a distinct a-b plane anisotropy beyond what is expected for structural origin. Such anisotropy in the longitudinal optical modes, which is absent in the TO, suggests strong in-plane anisotropy in the underlying electronic structure. Apical oxygen bond-stretching modes showed a large frequency change between the insulating and the metallic phases. This large softening also is beyond structural origin, and suggests the effect of local electronic environment.