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Monday, February 29, 2016

Lateral load test


When performing lateral load tests on deep foundations, it is
desirable to obtain horizontal displacement versus depth
profiles. These profiles can be used in conjunction with lateral

load versus displacement curves to calibrate lateral pile analysis
programs. In addition, the displacement versus depth curves
can be used to determine bending moment versus depth profiles.
Horizontal displacement versus depth profiles have typically
been determined using inclinometer probes or strings of
downhole inclinometers. Inclinometer probes require the user
to measure slope at 0.6 m intervals within a special grooved
pipe which is typically concreted into place within the pile. The
displacement of the pile must be held constant over a 15 to 20
minute period while the inclinometer measurements are made.
Strings of down hole inclinometers can also be installed at
various intervals within the inclinometer pipe. This option is
more expensive but allows measurements to be obtained
simultaneously and more quickly. Nevertheless, the
displacement of the foundation must be held relatively constant
for a several seconds so that the inclinometers can stabilize and
provide an accurate reading. This requirement usually
precludes their use for dynamic applications.


Staircase details and formula






























Sunday, February 28, 2016

Scientists have developed an ingenious way to trick cancer cells into eating drugs, and it works like a Trojan Horse.


Many cancers show primary or acquired drug resistance due to the overexpression of efflux pumps. A novel mechanism to circumvent this is to integrate drugs, such as anthracycline antibiotics, with nanoparticle delivery vehicles that can bypass intrinsic tumor drug-resistance mechanisms. DNA nanoparticles serve as an efficient binding platform for intercalating drugs (e.g., anthracyclines doxorubicin and daunorubicin, which are widely used to treat acute leukemias) and enable precise structure design and chemical modifications, for example, for incorporating targeting capabilities. Here, DNA nanostructures are utilized to circumvent daunorubicin drug resistance at clinically relevant doses in a leukemia cell line model. The fabrication of a rod-like DNA origami drug carrier is reported that can be controllably loaded with daunorubicin. It is further directly verified that nanostructure-mediated daunorubicin delivery leads to increased drug entry and retention in cells relative to free daunorubicin at equal concentrations, which yields significantly enhanced drug efficacy. Our results indicate that DNA origami nanostructures can circumvent efflux-pump-mediated drug resistance in leukemia cells at clinically relevant drug concentrations and provide a robust DNA nanostructure design that could be implemented in a wide range of cellular applications due to its remarkably fast self-assembly (≈5 min) and excellent stability in cell culture conditions.