5,163 research outputs found
Fluorescent labelling and biodistribution of latex nanoparticles formed by surfactant-free RAFT emulsion polymerisation
We report the preparation of a novel range of functional polyacrylamide stabilised polystyrene nanoparticles, obtained by surfactant-free reversible addition-fragmentation chain transfer (RAFT) emulsion polymerisation, their fluorescent tagging, cellular uptake and
biodistribution. We show the versatility of the RAFT emulsion process for the design of functional nanoparticles of well-defined size that can be used as drug delivery vectors.
Functionalisation with a fluorescent tag offers a useful visualisation tool for tracing, localisation and clearance studies of these carriers in biological models. The studies were carried out by labelling the sterically stabilised latex particles chemically with rhodamine B. The fluorescent particles were incubated in a healthy human renal proximal tubular cell line model, and intravenously injected into a mouse model. Cellular localisation and biodistribution of these particles on the biological models were explored
A Review of Hot Deck Imputation for Survey Non-response
L'imputation hot deck est une mĂ©thode de gestion des donnĂ©es manquantes dans laquelle chaque valeur manquante est remplacĂ©e par une rĂ©ponse observĂ©e Ă partir d'une unitĂ©âsimilaire.â Bien qu'elle soit largement utilisĂ©e en pratique, sa thĂ©orie n'est pas aussi dĂ©veloppĂ©e que celle des autres mĂ©thodes d'imputation. Nous avons constatĂ© qu'il n'existe aucun consensus quant Ă la meilleure faon d'appliquer les hot deck et obtenir des infĂ©rences Ă partir de la sĂ©rie de donnĂ©es complĂšte. Ici, nous passons en revue les diffĂ©rentes formes de hot deck et les recherches existantes sur ses propriĂ©tĂ©s statistiques. Nous dĂ©crivons les applications du hot deck actuellement utilisĂ©es, y compris le hot deck du Bureau US du recensement pour la Current Population Survey (CPS). Nous proposons aussi des exemples nombreux de variations du hot deck Ă la troisiĂšme National Health and Nutrition Examination Survey (NHANES III). Certains domaines possibles de recherches futures sont mises en Ă©vidence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78729/1/j.1751-5823.2010.00103.x.pd
Hepatitis B Sero-Prevalence and Risk Behaviors Among Immigrant Men in a Population-Based Household Survey in Low-Income Neighborhoods of Northern California
Background Despite an effective vaccine, 60,000 new HBV infections were reported in the US in 2004; 95% in adults. We evaluate HBV sero-prevalence, risk behaviors and self-reported vaccination among Latino immigrant, Asian immigrant and US born low income men in five northern California counties. Methods Population based, cross sectional survey of HBV sero-prevalence and risk behaviors in men aged 18 to 35Â years. Results Among 1,512 men screened, Asian immigrants were most likely to have had prior HBV infection (15.1%) and chronic infection (3.8%) compared to US born (prior 5.1%, chronic 0.6%) and Latino immigrant men (prior 2.0%, chronic 0.3%.) Reported HBV vaccination was lowest for Latino immigrants (12%) compared to Asian immigrants and US born men (35% in both.) Latino immigrants reported less educational attainment, medical insurance coverage and access to a physician in the last six months. Discussion Healthcare providers should routinely screen Asian immigrants for HBV regardless of their self reported vaccination status. Latino immigrants may comprise an important group of under-vaccinated, at risk persons in California. HBV testing and vaccination of immigrants soon after US arrival should be encouraged
Search for Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in e+e- Interactions at \sqrt{s} = 189 GeV
A search for the lightest neutral scalar and neutral pseudoscalar Higgs
bosons in the Minimal Supersymmetric Standard Model is performed using 176.4
pb^-1 of integrated luminosity collected by L3 at a center-of-mass energy of
189 GeV. No signal is observed, and the data are consistent with the expected
Standard Model background. Lower limits on the masses of the lightest neutral
scalar and pseudoscalar Higgs bosons are given as a function of tan(beta).
Lower mass limits for tan(beta)>1 are set at the 95% confidence level to be m_h
> 77.1 GeV and m_A > 77.1 GeV
Search for Extra Dimensions in Boson and Fermion Pair Production in e+e- Interactions at LEP
Extra spatial dimensions are proposed by recent theories that postulate the
scale of gravity to be of the same order as the electroweak scale. A sizeable
interaction between gravitons and Standard Model particles is then predicted.
Effects of these new interactions in boson and fermion pair production are
searched for in the data sample collected at centre-of-mass energies above the
Z pole by the L3 detector at LEP. In addition, the direct production of a
graviton associated with a Z boson is investigated. No statistically
significant hints for the existence of these effects are found and lower limits
in excess of 1 TeV are derived on the scale of this new theory of gravity
Measurement of the Probability of Gluon Splitting into Charmed Quarks in Hadronic Z Decays
We have measured the probability, n(g->cc~), of a gluon splitting into a
charm-quark pair using 1.7 million hadronic Z decays collected by the L3
detector. Two independent methods have been applied to events with a three-jet
topology. One method relies on tagging charmed hadrons by identifying a lepton
in the lowest energy jet. The other method uses a neural network based on
global event shape parameters. Combining both methods, we measure n(g->cc~)=
[2.45 +/- 0.29 +/- 0.53]%
Measurement of Triple-Gauge-Boson Couplings of the W Boson at LEP
We report on measurements of the triple-gauge-boson couplings of the W boson
in e+e- collisions with the L3 detector at LEP. W-pair, single-W and
single-photon events are analysed in a data sample corresponding to a total
luminosity of 76.7 pb^{-1} collected at centre-of-mass energies between 161 GeV
and 183 GeV. CP-conserving as well as both C- and P-conserving
triple-gauge-boson couplings are determined. The results, in good agreement
with the Standard-Model expectations, confirm the existence of the self
coupling among the electroweak gauge bosons and constrain its structure
Measurement of Hadron and Lepton-Pair Production at 130GeV < \sqrt{s} < 189 GeV at LEP
We report on measurements of e+e- annihilation into hadrons and lepton pairs.
The data have been collected with the L3 detector at LEP at centre-of-mass
energies between 130 and 189 GeV. Using a total integrated luminosity of 243.7
pb^-1, 25864 hadronic and 8573 lepton-pair events are selected for the
measurement of cross sections and leptonic forward-backward asymmetries. The
results are in good agreement with Standard Model predictions
Measurement of Mass and Width of the W Boson at LEP
We report on measurements of the mass and total decay width of the W boson
with the L3 detector at LEP. W-pair events produced in
interactions between 161 GeV and 183 GeV centre-of-mass energy are selected in
a data sample corresponding to a total luminosity of 76.7 pb. Combining
all final states in W-pair production, the mass and total decay width of the W
boson are determined to be GeV and
GeV, respectively
Formation of the in Two-Photon Collisions at LEP
The two-photon width of the meson has been
measured with the L3 detector at LEP. The is studied in the decay
modes , KK, KK,
KK, , , and
using an integrated luminosity of 140 pb at GeV and
of 52 pb at GeV. The result is
(BR) keV. The dependence of the cross section is studied for
GeV. It is found to be better described by a Vector Meson
Dominance model form factor with a J-pole than with a -pole. In addition,
a signal of events is observed at the mass. Upper limits
for the two-photon widths of the , , and are also
given
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