摘要:
Infection of human fibroblast cells with human cytomegalovirus (HCMV) causes down regulation of cell surface expression of MHC class I. The present invention is directed to a mutant with a 9-kb deletion in the S component of the HCMV genome (including open reading frames IRS1-US9 and US11) which failed to down regulate class I heavy chains. By examining the phenotypes of mutants with smaller deletions with this portion of the HCMV genome, a 7-kb region containing at least 9 open reading frames was shown to contain the genes required for reduction in heavy chain expression. Furthermore, it was determined that two subregions (A and B) of the 7-kb region each contained genes which were sufficient to cause heavy chain down regulation. In subregion B, the US11 gene product is involved. It encodes a endoglycosidase H-sensitive glycoprotein which is intracytoplasmic, similar to the adenovirus type 2 E3-19K glycoprotein which inhibits surface expression of class I heavy chains.
摘要:
Infection of human fibroblast cells with human cytomegalovirus (HCMV) causes down regulation of cell surface expression of MHC class I. The present invention is directed to a mutant with a 9-kb deletion in the S component of the HCMV genome (including open reading frames IRS1-US9 and US11) which failed to down regulate class I heavy chains. By examining the phenotypes of mutants with smaller deletions with this portion of the HCMV genome, a 7-kb region containing at least 9 open reading frames was shown to contain the genes required for reduction in heavy chain expression. Furthermore, it was determined that two subregions (A and B) of the 7-kb region each contained genes which were sufficient to cause heavy chain down regulation. In subregion B, the US11 gene product is involved. It encodes a endoglycosidase H-sensitive glycoprotein which is intracytoplasmic, similar to the adenovirus type 2 E3-19K glycoprotein which inhibits surface expression of class I heavy chains.
摘要:
Infection of human fibroblast cells with human cytomegalovirus (HCMV) causes down regulation of cell surface expression of MHC class I. The present invention is directed to a mutant with a 9-kb deletion in the S component of the HCMV genome (including open reading frames IRS1-US9 and US11) which failed to down regulate class I heavy chains. By examining the phenotypes of mutants with smaller deletions with this portion of the HCMV genome, a 7-kb region containing at least 9 open reading frames was shown to contain the genes required for reduction in heavy chain expression. Furthermore, it was determined that two subregions (A and B) of the 7-kb region each contained genes which were sufficient to cause heavy chain down regulation. In subregion B, the US11 gene product is involved. It encodes a endoglycosidase H-sensitive glycoprotein which is intracytoplasmic, similar to the adenovirus type 2 E3-19K glycoprotein which inhibits surface expression of class I heavy chains.
摘要:
Infection of human fibroblast cells with human cytomegalovirus (HCMV) causes down regulation of cell surface expression of MHC class I. The present invention is directed to a mutant with a 9-kb deletion in the S component of the HCMV genome (including open reading frames IRS1-US9 and US11) which failed to down regulate class I heavy chains. By examining the phenotypes of mutants with smaller deletions with this portion of the HCMV genome, a 7-kb region containing at least 9 open reading frames was shown to contain the genes required for reduction in heavy chain expression. Furthermore, it was determined that two subregions (A and B) of the 7-kb region each contained genes which were sufficient to cause heavy chain down regulation. In subregion B, the US11 gene product is involved. It encodes a endoglycosidase H-sensitive glycoprotein which is intracytoplasmic, similar to the adenovirus type 2 E3-19K glycoprotein which inhibits surface expression of class I heavy chains.
摘要:
A process for continuously separating relatively coarse particles from a suspension of a mixture of particles in a liquid wherein the suspension is caused to pass through a screening medium which is rotating in its own plane so that the coarse particles are retained on the surface of the screening medium; characterized in that atmospheric pressure above the screening medium is caused to be in excess of the pressure below that medium.
摘要:
There is provided a porous cellular material comprising a plurality of cavities each defined by a substantially spherical wall formed of a rigid intermeshing matrix of ceramic needles said wall being pierced by at least one aperture to provide access to the cavity, and the or each aperture having a diameter such that the ratio of the diameter of the aperture to the diameter of the cavity into which the aperture opens is in the range of from 0.1:1 to 1:1.
摘要:
There is disclosed a process for treating a clay mineral thereby to change its rheological properties when in aqueous suspension such that the fluidity of the aqueous suspension at a given temperature and percentage by weight of completely deflocculated clay mineral solids in the suspension is increased, which process comprises the steps of mixing with the clay mineral in a plastic state a minor proportion by weight of a water-soluble organic compound having a plurality of basic groups and a number average molecular weight not greater than 1000, and subsequently or simultaneously subjecting the mixture to mechanical working under conditions such that from 25 to 1000 KJ of energy per Kg of dry clay mineral are dissipated in the mixture.
摘要:
Color improved polyarylates having a reduced viscosity of from about 0.1 to greater than 1.0 dl/gm produced by a process comprising the following steps:(a) reacting an acid anhydride derived from an acid containing from 2 to 8 carbon atoms with at least one dihydric phenol to form the corresponding diester; and(b) reacting said diester with at least one aromatic dicarboxylic acid at a temperature sufficient to form the polyarylate, wherein the improvement comprises carrying out said process in the presence of a particular solid adsorbent.
摘要:
Optical article having a substrate with first and second surfaces and with a conductive antireflection coating disposed on the first surface. The conductive antireflection coating is comprised of at least one layer of a low index material carried by said first surface and a thin transparent conducting layer of a material having a high index of refraction carried by the layer of material having a low index of refraction. The conducting layer provides an exposed surface to which the direct electrical contact can be made. The conducting layer has an optical thickness ranging from 1.0 to 30.0 nanometers. The layer of material having a low index of refraction has its design thickness reduced to compensate for the thickness of the conducting layer whereby the conducting layer does not seriously degrade the optical performance of the coating over that which could be obtained without the use of the conducting layer.
摘要:
A circuit for controlling a valve assembly in applications where electrical isolation of the two control signal supply lines is required to prevent damage of control circuits caused by a reverse polarity feedback signal or other transient signal. The circuit includes a solenoid having a coil. The coil has a first end and a second end. The circuit also includes a first switching circuit electrically connected to the first and second ends of the coil to allow current to pass therethrough in a first direction to move a permanent magnet against a pushpin a first axial direction. The circuit further includes a second switching circuit electrically connected to the first and second ends of the coil to allow a current to pass therethrough in a second direction to move the permanent magnet away from the pushpin in a second axial direction. Further, when either switching circuit is allowing current to flow through the coil, it electrically isolates one negative control source from the other. The use of a pair of switching circuits electrically connected to the coil results in a relatively low voltage drop across the circuit.