96 research outputs found
Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP
Promptly decaying lightest neutralinos and long-lived staus are searched for
in the context of light gravitino scenarios. It is assumed that the stau is the
next to lightest supersymmetric particle (NLSP) and that the lightest
neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector
at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of
the production of these particles is found. Hence, lower mass limits for both
kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is
found to be greater than 71.5 GeV/c^2. In the search for long-lived stau,
masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10
to 150 \eVcc . Combining this search with the searches for stable heavy leptons
and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc
may be set for the stau mas
Hadronization properties of b quarks compared to light quarks in e+e- -> q qbar from 183 to 200 GeV
The DELPHI detector at LEP has collected 54 pb^{-1} of data at a
centre-of-mass energy around 183 GeV during 1997, 158 pb^{-1} around 189 GeV
during 1998, and 187 pb^{-1} between 192 and 200 GeV during 1999. These data
were used to measure the average charged particle multiplicity in e+e- -> b
bbar events, _{bb}, and the difference delta_{bl} between _{bb} and the
multiplicity, _{ll}, in generic light quark (u,d,s) events: delta_{bl}(183
GeV) = 4.55 +/- 1.31 (stat) +/- 0.73 (syst) delta_{bl}(189 GeV) = 4.43 +/- 0.85
(stat) +/- 0.61 (syst) delta_{bl}(200 GeV) = 3.39 +/- 0.89 (stat) +/- 1.01
(syst). This result is consistent with QCD predictions, while it is
inconsistent with calculations assuming that the multiplicity accompanying the
decay of a heavy quark is independent of the mass of the quark itself.Comment: 13 pages, 2 figure
In vivo antimicrobial and wound-healing activity of resveratrol, dihydroquercetin and dihydromyricetin against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans
An increase in the spread of antibiotic-resistant opportunistic microorganisms causes
serious problems in the treatment of purulent infections, burns, and trophic ulcers. We tested
the antimicrobial activity in vivo of three polyphenols, Resveratrol, Dihydroquercetin (Taxifolin),
and Dihydromyricetin (Ampelopsin) from Norway spruce bark to promote the elimination of
Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans from wounds. Purulent infection
was modelled on wounds in rats infected with suspensions containing 109 CFU (colony-forming
unit)/mL of pathogens. The wound area was treated daily with solutions of the polyphenols or
placebo for 14 days after the beginning of the treatment. The animals were examined daily, and each
stage of the wound healing (inflammation, granulation, and maturation (marginal epithelialisation)
was documented. The planimetric analysis of the wound recovery percentage was performed on
the 3rd, 10th, and 14th day after the start of curing. Then, one echelon (three or four animals from
each subgroup) was withdrawn from the experiment on days 3 (three animals), 10 (three animals),
and 14 (four animals) for microscopy analysis of cytological composition of their wound defects by
microscopy and microbiological analysis of their contamination with pathogens. Our results show
that they are also able to suppress mast cell infiltration and stimulate lymphocyte and macrophage
(monocyte) infiltration into the wound. Resveratrol stimulated the replacement of the scar with
normal tissue (with a clear boundary between the dermis and epidermis) and the restoration of
hair follicles. Resveratrol turned out to be significantly better than some commercial antimicrobial
(Levomecol) and antifungal (Clotrimazole) ointments and can be proposed as a promising drug for
topical use for the treatment of trophic ulcers and burns
Seasonal variation in the content of free reducing sugars in body fluids of freshwater mollusk Lymnaea stagnalis
Structural characterization of aqueous magnetic fluids with nanomagnetite of different origin stabilized by sodium oleate
Theoretical shear strength and the onset of plasticity in nanodeformation of cubic boron nitride
The nanoindentation in the continuous stiffness measurement mode was used to investigate the onset of plasticity at the nanodeformation of cubic boron nitride (cBN). This technique allows us to reveal an elastic-plastic transition in the contact and to measure the yield strength of cBN at the nanoscale. An abrupt elastoplastic transition (a pop-in) was observed in the (111) cBN single crystal as a result of a homogeneous or heterogeneous nucleation of dislocations in the previously dislocations-free region under the contact. The analysis of the data obtained at the homogeneous nucleation of dislocations in the contact region made it possible to experimentally estimate the theoretical shear strength of cBN and its ideal (elastic) hardness. In a sample of the fine-grained cBN with a nanotwinned substructure a smooth elastoplastic transition was observed in consequence of the propagation and multiplication of already existing dislocations in the contact region
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