Mass bounds in the standard model Clark, TE; Haeri, B; Love, ST ...
Physical review. D, Particles and fields,
07/1994, Letnik:
50, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Nonperturbative triviality and vacuum stability mass bounds are obtained for the Higgs scalar and top quark degrees of freedom in the standard electroweak model using Wilson renormalization group ...techniques. Particular attention is given to the effect of the generalized top Yukawa coupling on the scalar mass upper bound.
A 58-year-old woman who had presented with intestinal pseudo-obstruction died 9 months later from rapidly progressive neurologic symptoms and autonomic insufficiency. Her gastric emptying had been ...markedly delayed and transit of markers had been slowed throughout the small bowel. A 5-hour manometric recording of the antrum and duodenum had shown absence of the normal interdigestive motor complex, which was replaced by irregular contractile activity of reduced amplitude. A small-cell carcinoma of the lung was found at autopsy. Pathologic study of the gut showed widespread degeneration of the myenteric plexus, which was infiltrated by plasma cells and lymphocytes and contained significantly reduced numbers of neurons. The extra-intestinal nervous system had neuronal loss and lymphocytic infiltrates in dorsal root ganglia. Thus, a gastrointestinal neuropathy causing intestinal pseudo-obstruction may be the presenting manifestation of a paraneoplastic syndrome associated with small-cell carcinoma.
Behavior of TPCs in a high particle flux environment Etkin, A.; Eiseman, S.E.; Foley, K.J. ...
IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States),
08/1992, Letnik:
39, Številka:
4
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
TPCs (time projection chambers) used in E-810 at the AGS (alternating gradient synchrotron) were exposed to fluxes equivalent to more than 10/sup 7/ minimum ionizing particles per second to find if ...such high fluxes cause high changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (relativistic heavy ion collider) TPC-based experiments are discussed. Measurements of distortions due to ion loading in the E-810 TPCs have been measured to be small even at very high effective particle fluxes. This results supports the use of TPCs at RHIC, even at the highest planned luminosity. In addition, measurement of two-vertex resolution and reconstruction efficiency at high track density showed that a TPC is an excellent detector for the RHIC.< >
High depth resolution Rutherford scattering using forward angles Endisch, D.; Love, D.; Simpson, T.W. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
05/1995, Letnik:
100, Številka:
1
Journal Article
Recenzirano
Rutherford scattering of MeV
4He ions at forward angles has been used to determine the thickness and composition of single Si
1 −
x
Ge
x
layers in Si. With scattering angles of about 20° the obtained ...depth resolution is up to 25% better than with standard RBS at glancing backward angles. The large scattering cross section at forward angles allows for the use of a small solid angle while maintaining good count rates and short acquisition times. Geometrical broadening of the energy spectra, due to the finite acceptance angle of the detector, is thus negligible. The kinematic factor is close to 1 for almost all elements in this geometry. Layers with different composition are therefore only distinguishable by the differences in spectrum height. The best accuracy for the stoichiometry is obtained by combining the measured energy loss in a layer with the areal density of the heavier element in that layer, which can be determined by standard RBS. The results are compared to RBS and X-ray diffraction measurements. The influence of multiple scattering is illustrated and a comparison to depth resolution calculations with the DEPTH code is made.
Our method for constructing an antifibrin antibody-t-PA chimeric protein can be adapted to form other bifunctional, antibody-targeted proteins. Once an appropriate targeting antibody is obtained, the ...investigator can derive the heavy chain loss variant cell lines and clone the functional heavy chain rearrangement transcribed by the hybridoma. Other useful reagents include antisera directed against mouse Fab and antisera against whatever effector component is to be combined with the antibody. These are helpful during the screening of transfectants and the characterization of the secreted fusion protein, and they allow for protein purification by affinity chromatography. An assay of the functional activity of the effector domain is also desirable. The apparent retention of enzymatic activity and substrate specificity in our antibody-targeted plasminogen activator hybrid demonstrates that even complex molecules with strict folding requirements and multiple intrachain disulfide bonds can be used to form hybrid recombinant proteins. We have documented by electrophoretic transfer blotting that the heavy chain-t-PA fusion protein is secreted in association with light chain in the form of a 180-kDa dimer. The heavy chains appear to be attached by disulfide bonds at the hinge region, as is the case with the heavy chains of natural immunoglobulins. Our method can be adapted to various uses. More or less of the antibody constant region could be employed, depending on the desired geometry and the immunologic interactions mediated by the Fc domain. We have made a recombinant fusion peptide containing an additional 100 constant region amino acids but found that its targeting and catalytic abilities did not differ from those of the smaller molecule. Recent reports indicate that it is possible to express an antibody Fv that has full antigen recognition and binding properties; such small immunoglobulins could minimize potential immunogenicity while affording full targeting capability. The use of a human constant region sequence may also provide a less immunogenic molecule, and, by transferring the complementarity-determining regions of the monoclonal antibody into human variable region sequence, it may be possible to completely "humanize" an antibody-directed chimeric protein. The application of these and other innovative approaches should soon make antibodies an attractive means of targeting a wide range of molecules, both in scientific investigation and in medical therapy.
We show that the mouse gamma 2b heavy chain or human beta-globin 3' untranslated region can greatly enhance protein expression in myeloma cells transfected by genes coding for antibody-plasminogen ...activator fusion proteins. Expression plasmids were constructed containing a cloned genomic heavy chain variable region from fibrin-specific monoclonal antibody 59D8, a cloned genomic constant region of the mouse gamma 2b heavy chain, and DNA sequence coding for either tissue-type plasminogen activator (tPA) or a segment of urokinase (UK) and their respective 3' untranslated sequences. Cell lines transfected with these constructs, pSVtPA (tPA) and pSVUKG(UK), produced extremely low levels of mRNA and protein (0.008-0.06 micrograms/ml) in comparison with the parental 59D8 myeloma cell line (7.6-10 micrograms/ml). In vitro nuclear run-off analysis indicated that the low steady-state levels of mRNA encoded by pSVUKG(UK) did not result from a lower rate of transcription of the transfected gene (relative to the rate of transcription of the endogenous heavy chain gene in the 59D8 parent cells). In an attempt to increase protein secretion, we assembled the expression plasmids pSVtPA(Ig), pSVUKG(Ig), and pSVUKG(beta), in which the 3' untranslated region of the mouse gamma 2b heavy chain or human beta-globin gene was substituted for the 3' untranslated region of the plasminogen activator gene. Analysis of supernatant media from cell lines transfected with these constructs showed an increase in recombinant protein secretion of 68 to 100 fold in comparison with that from cell lines transfected with pSVtPA(tPA) or pSVUKG(UK).
Degenerative spondylolisthesis is four times more common in women than in men. Although this gender difference has long been recognised there has been no explanation for it. We have examined the ...radiographs and CT scans of 118 patients over the age of 55 years and of a control group under the age of 46 years. Our findings confirmed the presence of more sagittally-orientated facet joints in patients with degenerative spondylolisthesis but did not show that the gender difference can be explained by the morphology of the facet joint. Furthermore, we conclude that the increased angle of the facet joint is the result of arthritic remodelling and not the primary cause of degenerative spondylolisthesis. It is more likely to be due to loss of soft-tissue resilience with subsequent failure of the facet joints which are acting as the last restraints to subluxation.
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