摘要:
An attenuator for optical signals includes a base. A first ferrule has a first optic fiber passing through a central bore therein and attached to a first lens at an end of the first ferrule. The first ferrule is fixed in position relative to the base. A second ferrule has a second optic fiber passing through a central bore therein and attached to a second lens at an end of the second ferrule. The second lens faces the first lens. The second ferrule is fixed to the base and can be moved relative to the base by a user adjustment feature, so that the second lens may be moved relative to the first lens. The relative placement between the first and second lens controls the attenuation of the attenuator.
摘要:
The invention provides the components of in vivo and in vitro systems and methods which use them to study the effects of altered expression of a gene activity, such as the human akt, bcl-2, eIF4E or PTEN activities, on the descendants of stem cells that have been engineered to give rise to hematopoietic tumorigenic or tumor cells, such as lymphomas, with a high frequency. The present invention provides vectors, cells and mammals, and methods which in part depend on such products, useful for understanding tumorigenesis and its treatments, and in particular, for identifying and studying inhibitors and activators associated with tumor cell growth and growth inhibition, cell death through apoptotic pathways, and changes in apoptotic pathway components that affect drug sensitivity and resistance in tumorigenic cells. Methods for identifying molecular targets for drug screening, identifying interacting gene activities, for identifying therapeutic treatments and for identifying candidates for new therapeutic treatments are provided.
摘要:
The invention relates to recombinant vectors for inducible and/or tissue specific expression of double-stranded RNA molecules that interfere with the expression of a target gene. In certain embodiments, the invention relates to the use of Tet (tetracycline)-responsive RNA Polymerase II (Pol II) promoters (e.g., TetON or TetOFF) to direct inducible knockdown in certain cells of an integrated or an endogenous gene, such as p53. The invention also relates to a method for producing transgenic animals (e.g., mice) expressing inducible (such as tetracycline-regulated), reversible, and/or tissue-specific double-stranded RNA molecules that interfere with the expression of a target gene.
摘要:
This invention provides a genetically tractable in situ non-human animal model for hepatocellular carcinoma. The model is useful, inter alia, in understanding the molecular mechanisms of liver cancer, in understanding the genetic alterations that lead to chemoresistance or poor prognosis, and in identifying and evaluating new therapies against hepatocellular carcinomas. The liver cancer model of this invention is made by altering hepatocytes to increase oncogene expression, to reduce tumor suppressor gene expression or both and by transplanting the resulting hepatocytes into a recipient non-human animal.