Methoxycarbonyl-terminated hyperbranched poly(amine-ester) as templates for synthesis of silver nanoparticles

Highly stable and spherical silver nanoparticles, stabilized by methoxycarbonyl-terminated hyperbranched poly(amine-ester) (HPAE-COOCH₃), were synthesized in water with reducing AgNO₃/HPAE-COOCH₃ using two methods, viz. NaBH₄ and ultraviolet irradiation. HPAE-COOCH₃ was found to play a key role in the formation of nanoparticles. UV–visible absorption, Transmission electron microscopic (TEM), and Fourier transform infrared spectroscopy (FT-IR) had been used to study the structure and characterization of the silver nanoparticles. The absorption peaks of the silver nanoparticles appear at ~420 nm in UV–visible absorption spectra; average particle size reduced by NaBH₄ is ~30 nm, which is ~10 and ~15 nm, respectively, when ultraviolet irradiation time is 12 and 24 h. FT-IR spectra confirm that there is strong interaction between silver nanoparticles and HPAE-COOCH₃. And silver nanoparticles/HPAE-COOCH₃ aqueous solution can keep stable for more than 3 months.     

Asymptotic formulae for likelihood-based tests of new physics

We describe likelihood-based statistical tests for use in high energy physics for the discovery of new phenomena and for construction of confidence intervals on model parameters. We focus on the properties of the test procedures that allow one to account for systematic uncertainties. Explicit formulae for the asymptotic distributions of test statistics are derived using results of Wilks and Wald. We motivate and justify the use of a representative data set, called the “Asimov data set”, which provides a simple method to obtain the median experimental sensitivity of a search or measurement as well as fluctuations about this expectation.     

Observational constraints on decaying vacuum dark energy model

The decaying vacuum model (DV), treating dark energy as a varying vacuum, has been studied well recently. The vacuum energy decays linearly with the Hubble parameter in the late-times, ρ _Λ (t)∝H(t), and produces the additional matter component. We constrain the parameters of the DV model using the recent data-sets from supernovae, gamma-ray bursts, baryon acoustic oscillations, CMB, the Hubble rate and X-rays in galaxy clusters. It is found that the best fit of the matter density contrast Ω _m in the DV model is much lager than that in ΛCDM model. We give the confidence contours in the Ω _m –h plane up to 3σ confidence level. Besides, the normalized likelihoods of Ω _m and h are presented, respectively.     

Towards Higgs boson production in gluon fusion to NNLO in the MSSM

We consider the Higgs boson production in the gluon-fusion channel to next-to-next-to-leading order within the Minimal Supersymmetric Standard Model. In particular, we present analytical results for the matching coefficient of the effective theory and study its influence on the total production cross section in the limit where the masses of all MSSM particles coincide. For supersymmetric masses below 500 GeV it is possible to find parameters leading to a significant enhancement of the Standard Model cross section, the K-factors, however, change only marginally.     

Dysregulation of chemo-cytokine production in schizophrenic patients versus healthy controls

Background  

The exact cause of schizophrenia is not known, although several aetiological theories have been proposed for the disease, including developmental or neurodegenerative processes, neurotransmitter abnormalities, viral infection and immune dysfunction or autoimmune mechanisms. Growing evidence suggests that specific cytokines and chemokines play a role in signalling the brain to produce neurochemical, neuroendocrine, neuroimmune and behavioural changes. A relationship between inflammation and schizophrenia was supported by abnormal cytokines production, abnormal concentrations of cytokines and cytokine receptors in the blood and cerebrospinal fluid in schizophrenia. Since the neuropathology of schizophrenia has recently been reported to be closely associated with microglial activation we aimed to determined whether spontaneous or LPS-induced peripheral blood mononuclear cell chemokines and cytokines production is dysregulated in schizophrenic patients compared to healthy subjects. We enrolled 51 untreated first-episode schizophrenics (SC) and 40 healthy subjects (HC) and the levels of MCP-1, MIP-1α, IL-8, IL-18, IFN-γ and RANTES were determined by Elisa method in cell-free supernatants of PBMC cultures.     

WIMP event rates in directional experiments: The diurnal variation signature

The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Modern particle theories provide viable cold dark matter candidates with masses in the GeV-TeV region. All such candidates will be called WIMPs (Weakly Interacting Massive Particles). The nature of dark matter can only be unraveled by its direct detection in the laboratory. In this work we present some theoretical elements relevant to the direct dark matter detection experiments, paying particular attention to directional experiments, i.e. experiments in which not only the energy but the direction of the recoiling nucleus is observed. Since the direction of observation is fixed with respect to the Earth, while the Earth is rotating around its axis, in a directional experiment the angle between the direction of observation and the Sun’s direction of motion will change during the day. So, since the event rates sensitively depend on this angle, the observed signal in such experiments will exhibit very interesting and characteristic periodic diurnal variation.     

Organization of matter into one-dimensional units on designed media

The organization of magnetic materials into one-dimensional micro- and nanowires on designed media is discussed, exemplified by two experiments on the microscale and nanoscale, with regard to particles as basic building blocks for the growth and development of matter.     

Wigner function and Bell’s inequalities for even and odd coherent states

The Wigner function and the symplectic tomogram of an entangled quantum state, which is a superposition of the photon’s coherent states (even and odd coherent states), is studied. Photon statistics and violation of Bell’s inequality for the photon state are discussed.     

A diffractive optical element for shaping arbitrary beams

A design method is presented for an optical element that shapes an arbitrary collimated beam. The optical element consists of a pair of diffractive optical elements (DOEs). The outgoing beam is also collimated, and can have any desired intensity profile. The phase functions of the DOEs are computed by minimizing an appropriate cost function under an energy conservation constraint.     

LD-end-pumped Nd:YAP laser operating at 1341.4 nm and doubling of its frequency

We report an LD-end-pumped linearly-polarized continuous-wave (CW) Nd:YAP laser operating at 1341.4 nm. Making use of the plane-concave resonator (T = 2.4%) and the plane-plane resonator (T = 2.6%), we obtain linearly-polarized laser radiation at 1341.4 nm with a power of 3.15 and 2.86 W and corresponding optical slope efficiency of 18.4 and 17.5%, respectively. The effect of the laser oscillation mode on the output is analyzed. An experiment on the intra-cavity frequency doubling with an LBO crystal has been performed, and a laser power of 431 mW in one direction at 670.7 nm was obtained.