848 research outputs found
Technical Advances in Skin Sparing Mastectomy
Skin sparing mastectomy has resulted in marked improvement in the aesthetic results of immediate breast reconstruction. Mature data has confirmed its oncological safety in the treatment of breast cancer. The procedure has gained wide acceptance and has undergone numerous technical advances since its introduction over twenty years ago. Careful patient selection and choice of skin incisions are necessary to avoid complications
Very light CP-odd scalar in the Two-Higgs-Doublet Model
We show that a general two-Higgs-doublet model (THDM) with a very light
CP-odd scalar (A) can be compatible with the rho parameter, Br(b --> s\gamma),
R_b, A_b, (g-2) of muon, Br(Upsilon --> A gamma), and the direct search via the
Yukawa process at LEP. For its mass around 0.2 GeV, the muon (g-2) and
Br(Upsilon --> A \gamma) data require tan(beta) to be about 1. Consequently, A
can behave like a fermiophobic CP-odd scalar and predominantly decay into a
photon pair ("gamma gamma"), which registers in detectors of high energy
collider experiments as a single photon signature when the momentum of A is
large. We compute the partial decay width of Z --> A A A and the production
rate of f \bar{f} --> Z A A --> Z +"gamma gamma", f^' {\bar f} --> W^{\pm} A A
--> W^\pm + "gamma gamma" and f \bar f --> H^+ H^- --> W^+ W^- A A --> W^+ W^-
+ "gamma gamma" at high energy colliders such as LEP, Tevatron, LHC, and future
Linear Colliders. Other production mechanisms of a light A, such as gg --> h
--> AA --> "gamma gamma", are also discussed.Comment: Some improvementes, references updated, 3 new figures, one new
appendix, abstract and conclusions unchaged. Version to appear in Physical
Review
Theoretical Aspects of Charge Ordering in Molecular Conductors
Theoretical studies on charge ordering phenomena in quarter-filled molecular
(organic) conductors are reviewed. Extended Hubbard models including not only
the on-site but also the inter-site Coulomb repulsion are constructed in a
straightforward way from the crystal structures, which serve for individual
study on each material as well as for their systematic understandings. In
general the inter-site Coulomb interaction stabilizes Wigner crystal-type
charge ordered states, where the charge localizes in an arranged manner
avoiding each other, and can drive the system insulating. The variety in the
lattice structures, represented by anisotropic networks in not only the
electron hopping but also in the inter-site Coulomb repulsion, brings about
diverse problems in low-dimensional strongly correlated systems. Competitions
and/or co-existences between the charge ordered state and other states are
discussed, such as metal, superconductor, and the dimer-type Mott insulating
state which is another typical insulating state in molecular conductors.
Interplay with magnetism, e.g., antiferromagnetic state and spin gapped state
for example due to the spin-Peierls transition, is considered as well. Distinct
situations are pointed out: influences of the coupling to the lattice degree of
freedom and effects of geometrical frustration which exists in many molecular
crystals. Some related topics, such as charge order in transition metal oxides
and its role in new molecular conductors, are briefly remarked.Comment: 21 pages, 19 figures, to be published in J. Phys. Soc. Jpn. special
issue on "Organic Conductors"; figs. 4 and 11 replaced with smaller sized
fil
Providing Adaptive and Evolving Government E-Services through Citizen-Centric Process Views
Induced Fit or Conformational Selection? The Role of the Semi-closed State in the Maltose Binding Protein
On the Action of Cyclosporine A, Rapamycin and Tacrolimus on M. avium Including Subspecies paratuberculosis
BACKGROUND: Mycobacterium avium subspecies paratuberculosis (MAP) may be zoonotic. Recently the "immuno-modulators" methotrexate, azathioprine and 6-MP and the "anti-inflammatory" 5-ASA have been shown to inhibit MAP growth in vitro. We concluded that their most plausible mechanism of action is as antiMAP antibiotics. The "immunosuppressants" Cyclosporine A, Rapamycin and Tacrolimus (FK 506) treat a variety of "autoimmune" and "inflammatory" diseases. Rapamycin and Tacrolimus are macrolides. We hypothesized that their mode of action may simply be to inhibit MAP growth. METHODOLOGY: The effect on radiometric MAP (14)CO(2) growth kinetics of Cyclosporine A, Rapamycin and Tacrolimus on MAP cultured from humans (Dominic & UCF 4) or ruminants (ATCC 19698 & 303) and M. avium subspecies avium (ATCC 25291 & 101) are presented as "percent decrease in cumulative GI" (%-DeltacGI.) PRINCIPAL FINDINGS: The positive control clofazimine has 99%-DeltacGI at 0.5 microg/ml (Dominic). Phthalimide, a negative control has no dose dependent inhibition on any strain. Against MAP there is dose dependent inhibition by the immunosuppressants. Cyclosporine has 97%-DeltacGI by 32 microg/ml (Dominic), Rapamycin has 74%-DeltacGI by 64 microg/ml (UCF 4) and Tacrolimus 43%-DeltacGI by 64 microg/ml (UCF 4) CONCLUSIONS: We show heretofore-undescribed inhibition of MAP growth in vitro by "immunosuppressants;" the cyclic undecapeptide Cyclosporine A, and the macrolides Rapamycin and Tacrolimus. These data are compatible with our thesis that, unknowingly, the medical profession has been treating MAP infections since 1942 when 5-ASA and subsequently azathioprine, 6-MP and methotrexate were introduced in the therapy of some "autoimmune" and "inflammatory" diseases
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