1,283 research outputs found
Supersymmetric particle mass measurement with the boost-corrected contransverse mass
A modification to the contransverse mass (MCT) technique for measuring the
masses of pair-produced semi-invisibly decaying heavy particles is proposed in
which MCT is corrected for non-zero boosts of the centre-of-momentum (CoM)
frame of the heavy states in the laboratory transverse plane. Lack of knowledge
of the mass of the CoM frame prevents exact correction for this boost, however
it is shown that a conservative correction can nevertheless be derived which
always generates an MCT value which is less than or equal to the true value of
MCT in the CoM frame. The new technique is demonstrated with case studies of
mass measurement with fully leptonic ttbar events and with SUSY events
possessing a similar final state.Comment: 33 pages, 33 .eps figures, JHEP3 styl
Oxygen-Vacancy-Induced Orbital Reconstruction of Ti Ions at the Interface of LaAlO3/SrTiO3 Heterostructures: A Resonant Soft-X-Ray Scattering Study
Resonant soft-x-ray scattering measurements have been performed to investigate interface electronic structures of (LaAlO3/SrTiO3) superlattices. Resonant scattering intensities at superlattice reflections show clear evidence of degeneracy lifting in t(2g) states of interface Ti ions. Polarization dependence of intensities indicates the energy of d(xy) states is lower by similar to 1 eV than two other t(2g) states. The energy splitting is insensitive to epitaxial strain. The orbital reconstruction is induced by oxygen vacancies and confined to the interface within two unit cells, indicating charge compensation at the polar interfaces. DOI: 10.1103/PhysRevLett.110.017401X112723Nsciescopu
Light Sneutrino Dark Matter at the LHC
In supersymmetric (SUSY) models with Dirac neutrino masses, a weak-scale
trilinear A-term that is not proportional to the small neutrino Yukawa
couplings can induce a sizable mixing between left and right-handed sneutrinos.
The lighter sneutrino mass eigenstate can hence become the lightest SUSY
particle (LSP) and a viable dark matter candidate. In particular, it can be an
excellent candidate for light dark matter with mass below ~10 GeV. Such a light
mixed sneutrino LSP has a dramatic effect on SUSY signatures at the LHC, as
charginos decay dominantly into the light sneutrino plus a charged lepton, and
neutralinos decay invisibly to a neutrino plus a sneutrino. We perform a
detailed study of the LHC potential to resolve the light sneutrino dark matter
scenario by means of three representative benchmark points with different
gluino and squark mass hierarchies. We study in particular the determination of
the LSP (sneutrino) mass from cascade decays involving charginos, using the mT2
variable. Moreover, we address measurements of additional invisible sparticles,
in our case the lightest neutralino, and the question of discrimination against
the MSSM.Comment: 25 pages, 16 figure
Pharmacokinetic Interactions Between the Fixed-Dose Combination of Ezetimibe/Rosuvastatin 10/20 Mg and the Fixed-Dose Combination of Telmisartan/Amlodipine 80/5 Mg in Healthy Subjects
Hyunwook Ryu,1 Hyun Chul Kim,1 Inseung Jeon,1 In-Jin Jang,1 Joo-Youn Cho,1,2 Kyung Tae Kim,3 Jaeseong Oh1,4,5 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea; 2Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea; 3Addpharma, Inc., Yongin-si, Gyeonggi-do, Republic of Korea; 4Department of Pharmacology, Jeju National University College of Medicine, Jeju, Republic of Korea; 5Clinical Research Institute, Jeju National University Hospital, Jeju, Republic of KoreaCorrespondence: Jaeseong Oh, Department of Pharmacology, Jeju National University College of Medicine, Jeju, Republic of Korea, Email [email protected]: Management of hypertension and hyperlipidemia, which are common comorbid risk factors for cardiovascular diseases, require multiple medications. The development of a fixed-dose combination (FDC) containing ezetimibe, rosuvastatin, telmisartan, and amlodipine aims to enhance patient adherence and persistence, but the potential interactions among the four medications have not been studied. This study aimed to evaluate the pharmacokinetic (PK) interactions between the FDC of ezetimibe/rosuvastatin 10/20 mg (ER) and the FDC of telmisartan/amlodipine 80/5 mg (TA).Methods: An open-label, single-sequence, three-period, three-treatment crossover study was conducted in healthy male subjects. All subjects received ER for 7 days, TA for 9 days and ER combined with TA for 7 days during each treatment period. For PK analysis of total/free ezetimibe, rosuvastatin, telmisartan, and amlodipine, serial blood samples were collected for 24 hours at steady state. Safety profiles were assessed throughout the study.Results: Thirty-eight subjects were enrolled, and 34 subjects completed the study. The systemic exposure to each active ingredient after coadministration of the two FDCs was similar to that after each FDC alone. The geometric mean ratios and 90% confidence intervals for the maximum plasma concentration (μg/L) and the area under the plasma concentration-time curve (h·μg/L) of the combination therapy to monotherapy, assessed at steady state, were as follows: total ezetimibe, 1.0264 (0.8765– 1.2017) and 0.9359 (0.7847– 1.1163); free ezetimibe, 1.5713 (1.2821– 1.9257) and 0.9941 (0.8384– 1.1788); rosuvastatin, 2.1673 (1.7807– 2.6379) and 1.1714 (0.9992– 1.3733); telmisartan, 1.0745 (0.8139– 1.4186) and 1.1057 (0.8379– 1.4591); and amlodipine, 0.9421 (0.8764– 1.0126) and 0.9603 (0.8862– 1.0405). Both combination therapy and monotherapy were well tolerated by the subjects.Conclusion: The coadministration of ezetimibe/rosuvastatin 10/20 mg and ezetimibe/rosuvastatin 10/20 mg was well tolerated in healthy subjects, and the PK interaction between those two FDCs was not clinically significant.Keywords: drug‒drug interactions, pharmacokinetics, fixed-dose combination, ezetimibe, rosuvastatin, telmisartan, amlodipin
Spin and Chirality Effects in Antler-Topology Processes at High Energy Colliders
We perform a model-independent investigation of spin and chirality
correlation effects in the antler-topology processes
at high energy colliders with polarized
beams. Generally the production process
can occur not only through the -channel exchange of vector bosons,
, including the neutral Standard Model (SM) gauge bosons,
and , but also through the - and -channel exchanges of new
neutral states, and , and the -channel
exchange of new doubly-charged states, . The general set of
(non-chiral) three-point couplings of the new particles and leptons allowed in
a renormalizable quantum field theory is considered. The general spin and
chirality analysis is based on the threshold behavior of the excitation curves
for pair production in collisions with
longitudinal and transverse polarized beams, the angular distributions in the
production process and also the production-decay angular correlations. In the
first step, we present the observables in the helicity formalism. Subsequently,
we show how a set of observables can be designed for determining the spins and
chiral structures of the new particles without any model assumptions. Finally,
taking into account a typical set of approximately chiral invariant scenarios,
we demonstrate how the spin and chirality effects can be probed experimentally
at a high energy collider.Comment: 50 pages, 14 figures, 6 tables, matches version published in EPJ
Measuring Invisible Particle Masses Using a Single Short Decay Chain
We consider the mass measurement at hadron colliders for a decay chain of two
steps, which ends with a missing particle. Such a topology appears as a
subprocess of signal events of many new physics models which contain a dark
matter candidate. From the two visible particles coming from the decay chain,
only one invariant mass combination can be formed and hence it is na\"ively
expected that the masses of the three invisible particles in the decay chain
cannot be determined from a single end point of the invariant mass
distribution. We show that the event distribution in the
vs. invariant mass-squared plane, where , are the transverse
energies of the two visible particles, contains the information of all three
invisible particle masses and allows them to be extracted individually. The
experimental smearing and combinatorial issues pose challenges to the mass
measurements. However, in many cases the three invisible particle masses in the
decay chain can be determined with reasonable accuracies.Comment: 45 pages, 32 figure
A statistical model that predicts the length from the left subclavian artery to the celiac axis; towards accurate intra aortic balloon sizing
<p>Abstract</p> <p>Background</p> <p>Ideally the length of the Intraaortic balloon membrane (22-27.5 cm) should match to the distance from the left subclavian artery (LSA) to the celiac axis (CA), (LSA - CA). By being able to estimate this distance, better guidance regarding IABP sizing could be recommended.</p> <p>Methods</p> <p>Internal aortic lengths and demographic values were collected from a series of 40 cadavers during autopsy. External somatometric measurements were also obtained.</p> <p>There were 23 males and 17 females. The mean age was 73.1+/-13.11 years, weight 56.75+/-12.51 kg and the height 166+/-9.81 cm.</p> <p>Results</p> <p>Multiple regression analysis revealed the following predictor variables (R2 > 0.70) for estimating the length from LSA to CA: height (standardized coefficient (SRC) = 0.37, p = 0.004), age (SRC = 0.35, p < 0.001), sex (SRC = 0.21, p = 0.088) and the distance from the jugular notch to trans-pyloric plane (SRC = 0.61, p < 0.001).</p> <p>Recommendations: If LSA-CA < 21.9 cm use 34 cc IABP & if LSA-CA > 26.3 cm use 50 cc IABP. However if LSA-CA = 21.9- 26.3 cm use 40 cc, but be aware that it could be "aortic length-balloon membrane length" mismatching.</p> <p>Conclusions</p> <p>Routinely, IABP size selection is being dictated by the patient's height. Inevitably, this leads to pitfalls. We reported a mathematical model of accurate intraaortic balloon sizing, which is easy to be applied and has a high predictive value.</p
Induction of aromatic ring: cleavage dioxygenases in Stenotrophomonas maltophilia strain KB2 in cometabolic systems
Stenotrophomonas maltophilia KB2 is known to produce different enzymes of dioxygenase family. The aim of our studies was to determine activity of these enzymes after induction by benzoic acids in cometabolic systems with nitrophenols. We have shown that under cometabolic conditions KB2 strain degraded 0.25–0.4 mM of nitrophenols after 14 days of incubation. Simultaneously degradation of 3 mM of growth substrate during 1–3 days was observed depending on substrate as well as cometabolite used. From cometabolic systems with nitrophenols as cometabolites and 3,4-dihydroxybenzoate as a growth substrate, dioxygenases with the highest activity of protocatechuate 3,4-dioxygenase were isolated. Activity of catechol 1,2- dioxygenase and protocatechuate 4,5-dioxygenase was not observed. Catechol 2,3-dioxygenase was active only in cultures with 4-nitrophenol. Ability of KB2 strain to induce and synthesize various dioxygenases depending on substrate present in medium makes this strain useful in bioremediation of sites contaminated with different aromatic compounds
Pyrosequencing Revealed SAR116 Clade as Dominant dddP-Containing Bacteria in Oligotrophic NW Pacific Ocean
Dimethyl sulfide (DMS) is a climatically active gas released into the atmosphere from oceans. It is produced mainly by bacterial enzymatic cleavage of dimethylsulfoniopropionate (DMSP), and six DMSP lyases have been identified to date. To determine the biogeographical distribution of bacteria relevant to DMS production, we investigated the diversity of dddP-the most abundant DMS-producing gene-in the northwestern Pacific Ocean using newly developed primers and the pyrosequencing method. Consistent with previous studies, the major dddP-containing bacteria in coastal areas were those belonging to the Roseobacter clade. However, genotypes closely related to the SAR116 group were found to represent a large portion of dddP-containing bacteria in the surface waters of the oligotrophic ocean. The addition of DMSP to a culture of the SAR116 strain Candidatus Puniceispirillum marinum IMCC1322 resulted in the production of DMS and upregulated expression of the dddP gene. Considering the large area of oligotrophic water and the wide distribution of the SAR116 group in oceans worldwide, we propose that these bacteria may play an important role in oceanic DMS production and biogeochemical sulfur cycles, especially via bacteriamediated DMSP degradation.open1178sciescopu
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