60 research outputs found
Phenomenology of NMSSM in TeV scale mirage mediation
We study the next-to-minimal supersymmetric standard model (NMSSM) with the
TeV scale mirage mediation, which is known as a solution for the little
hierarchy problem in supersymmetry. Our previous study showed that 125 GeV
Higgs boson is realized with O(10) % fine-tuning for 1.5 TeV gluino (1 TeV
stop) mass. The term could be as large as 500 GeV without sacrificing the
fine-tuning thanks to a cancellation mechanism. The singlet-doublet mixing is
suppressed by . In this paper, we further extend this analysis. We
argue that approximate scale symmetries play a role behind the suppression of
the singlet-doublet mixing. They reduce the mixing matrix to a simple form that
is useful to understand the results of the numerical analysis. We perform a
comprehensive analysis of the fine-tuning including the singlet sector by
introducing a simple formula for the fine-tuning measure. This shows that the
singlet mass of the least fine-tuning is favored by the LEP anomaly for
moderate . We also discuss prospects for the precision measurements
of the Higgs couplings at LHC and ILC and direct/indirect dark matter searches
in the model.Comment: 47 pages, 46 figures, version accepted by JHE
Tubular Injury in a Rat Model of Type 2 Diabetes Is Prevented by Metformin: A Possible Role of HIF-1α Expression and Oxygen Metabolism
http://dx.doi.org/10.2337/db10-0655OBJECTIVE : Chronic hypoxia has been recognized as a key regulator in renal tubulointerstitial fibrosis, as seen in diabetic nephropathy, which is associated with the activation of hypoxia-inducible factor (HIF)-1α. We assess here the effects of the biguanide, metformin, on the expression of HIF-1α in diabetic nephropathy using renal proximal tubular cells and type 2 diabetic rats. RESEARCH DESIGN AND METHODS : We explored the effects of metformin on the expression of HIF-1α using human renal proximal tubular epithelial cells (HRPTECs). Male Zucker diabetic fatty (ZDF; Gmi-fa/fa) rats were treated from 9 to 39 weeks with metformin (250 mg/kg^/day^) or insulin. RESULTS : Metformin inhibited hypoxia-induced HIF-1α accumulation and the expression of HIF-1–targeted genes in HRPTECs. Although metformin activated the downstream pathways of AMP-activated protein kinase (AMPK), neither the AMPK activator, AICAR, nor the mTOR inhibitor, rapamycin, suppressed hypoxia-induced HIF-1α expression. In addition, knockdown of AMPK-α did not abolish the inhibitory effects of metformin on HIF-1α expression. The proteasome inhibitor, MG-132, completely eradicated the suppression of hypoxia-induced HIF-1α accumulation by metformin. The inhibitors of mitochondrial respiration similarly suppressed hypoxia-induced HIF-1α expression. Metformin significantly decreased ATP production and oxygen consumption rates, which subsequently led to increased cellular oxygen tension. Finally, metformin, but not insulin, attenuated tubular HIF-1α expression and pimonidazole staining and ameliorated tubular injury in ZDF rats. CONCLUSIONS : Our data suggest that hypoxia-induced HIF-1α accumulation in diabetic nephropathy could be suppressed by the antidiabetes drug, metformin, through the repression of oxygen consumption
TeV scale mirage mediation in NMSSM
We study the next-to-minimal supersymmetric standard model. We consider soft
supersymmetry breaking parameters, which are induced by the mirage mediation
mechanism of supersymmetry breaking. We concentrate on the mirage mediation,
where the so-called mirage scale is the TeV scale. In this scenario, we can
realize the up-type Higgs soft mass of O(200) GeV, while other masses such as
gaugino masses and stop masses are heavy such as 1 TeV or more. Cancellation
between the effective \mu-term and the down-type Higgs soft mass ameliorates
the fine-tuning in the electroweak symmetry breaking even for \mu=O(500) GeV.
The mixing between the doublet and singlet Higgs bosons is suppressed by
(\lambda/\kappa)/tan\beta. Then the lightest doublet Higgs mass naturally
reaches 125 GeV lifted by the new quartic coupling. The higgsino and singlino
are light and their linear combination is the lightest superparticle.Comment: 24 pages, 24 figures, Numerical analysis is replaced with the version
calculated by NMSSMTools. Comments and references are added on the suppressed
doublet-singlet mixing and cases in which the 125 GeV boson is the 2nd
lightest CP-even scalar. The version accepted by JHE
Clinical Study A Randomized Prospective Study of Bowel Preparation for Colonoscopy with Low-Dose Sodium Phosphate Tablets versus Polyethylene Glycol Electrolyte Solution
Optimal bowel preparation is essential for the safety and outcome of colonoscopy. A solution containing polyethylene glycol (PEG) is often used as a bowel cleansing agent, but some patients are intolerant of PEG, and this may lead to discontinuation of colonoscopy. Sodium phosphates (NaP) tablets are designed to improve patient acceptance and compliance. The objective of this study was to compare bowel preparation efficiency and patient acceptance of a 30 NaP tablet preparation (L-NaP) and a 2 L PEG preparation. Patients were randomized into either the L-NaP or PEG group. The primary endpoint was the efficiency of colon cleansing as assessed by a validated four-point scale according to the Aronchick scale by endoscopists and was verified by blinded investigators. The secondary endpoints were patients' tolerability and acceptance. Colon-cleansing efficiency was not significantly different between the two preparations. However, patients' overall judgment was significantly in favor of L-NaP, reflecting better acceptance of L-NaP than PEG. Additionally, more patients favored L-NaP over PEG in a hypothetical future occasion requiring colonoscopy
Successful remission of ulcerative colitis flare-up during pregnancy with adsorptive granulomonocytapheresis plus tacrolimus
Ulcerative colitis (UC) is 1 of the 2 major phenotypes of chronic inflammatory bowel disease (IBD), which afflicts millions of individuals throughout the world with debilitating symptoms that impair function and quality of life. Further, IBD often affects women during childbearing age. Indeed, UC activity frequently increases during pregnancy, and the medications used to induce remission may adversely affect the health of the mother and the unborn child. We report successful induction of a remission in a UC case who experienced a flare-up in the first trimester of pregnancy. Upon relapse, she was treated with steroids and adsorptive granulomonocytapheresis (GMA) with the Adacolumn plus tacrolimus. This combination therapy induced a stable remission that was maintained during her entire pregnancy. She gave birth to a healthy child at 36 weeks of pregnancy with no maternal or fetal complications. Our experience indicates that GMA, as a non-drug therapeutic intervention with a favorable safety profile, plus tacrolimus might be a relevant treatment option for patients with active IBD during pregnancy. A future study of a large cohort of pregnant patients should strengthen our findings
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