3,556 research outputs found
Dermatitis crónica por sensibilización al níquel en un paciente con fractura del astrágalo tratada mediante osteosíntesis
Se presenta un varón de 25 años, con fractura del astrágalo izquierdo tratada
mediante osteosíntesis con 2 tornillos de acero inoxidable con un contenido en níquel del 12-14%.
A los 4 meses de la intervención, el paciente desarrolló una dermatitis pruriginosa en cara
lateral externa del pie, en la zona cutánea supra-adyacente al lugar de la osteosíntesis. La lesión
no cedió con el tratamiento tópico convencional a base de corticoides. Las pruebas epicutáneas
realizadas con la batería estándar del Grupo Español de Investigación en Dermatitis
de Contacto revelaron un parche positivo vesiculoso (+ +) al sulfato de níquel al 2,5% y al
cloruro de cobalto al 1%, ambos aplicados en vaselina, en la lectura a las 48 y 96 horas. En
vista de que las lesiones permanecían estables al mes de tratamiento con un potente corticoide
en cura oclusiva y antihistamínicos sistémicos, se procedió a retirar los tornillos de osteosíntesis.
A los pocos días de la intervención comenzó a desaparecer el prurito y, en el curso de
2 semanas, se produjo la curación completa de la dermatitisSe presenta un varón de 25 años, con fractura del astrágalo izquierdo tratada
mediante osteosíntesis con 2 tornillos de acero inoxidable con un contenido en níquel del 12-14%.
A los 4 meses de la intervención, el paciente desarrolló una dermatitis pruriginosa en cara
lateral externa del pie, en la zona cutánea supra-adyacente al lugar de la osteosíntesis. La lesión
no cedió con el tratamiento tópico convencional a base de corticoides. Las pruebas epicutáneas
realizadas con la batería estándar del Grupo Español de Investigación en Dermatitis
de Contacto revelaron un parche positivo vesiculoso (+ +) al sulfato de níquel al 2,5% y al
cloruro de cobalto al 1%, ambos aplicados en vaselina, en la lectura a las 48 y 96 horas. En
vista de que las lesiones permanecían estables al mes de tratamiento con un potente corticoide
en cura oclusiva y antihistamínicos sistémicos, se procedió a retirar los tornillos de osteosíntesis.
A los pocos días de la intervención comenzó a desaparecer el prurito y, en el curso de
2 semanas, se produjo la curación completa de la dermatitis
Memorino on the `1/2 vs. 3/2 Puzzle' in
After the successes the OPE description has scored in describing decays, we need to study what can be said about the composition
of the hadronic final state . The same OPE treatment yields sum rules
implying the dominance of charm states in over their
counterparts. This prediction is supported by other general arguments
as well as quark model calculations. At present it is unclear to which degree
data conform to these predictions. More experimental information is essential.
We want to ask our experimental colleagues for a redoubled effort to establish,
which hadronic configurations -- -- make up
beyond , what
their quantum numbers are and their mass distributions. The latter is most
relevant for the determination of hadronic mass moments in . Since all this will require considerable effort on their part, we
want to explain the theoretical issues involved, why they carry `gravitas' --
i.e. are weighty -- and why a better understanding of them will be of
significant value. In this brief memo we sketch the underlying arguments based
on heavy quark theory, the OPE, a special class of quark models and lattice QCD
in a nutshell. After summarizing the experimental situation we conclude with
two lists, namely one with measurements that need to be done and one with items
of theoretical homework. Some of the latter can be done by employing existing
theoretical tools, whereas others need new ideas.Comment: 13 pages, no figure
Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−
The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions
Observation of two new baryon resonances
Two structures are observed close to the kinematic threshold in the mass spectrum in a sample of proton-proton collision data, corresponding
to an integrated luminosity of 3.0 fb recorded by the LHCb experiment.
In the quark model, two baryonic resonances with quark content are
expected in this mass region: the spin-parity and
states, denoted and .
Interpreting the structures as these resonances, we measure the mass
differences and the width of the heavier state to be
MeV,
MeV,
MeV, where the first and second
uncertainties are statistical and systematic, respectively. The width of the
lighter state is consistent with zero, and we place an upper limit of
MeV at 95% confidence level. Relative
production rates of these states are also reported.Comment: 17 pages, 2 figure
Study of DJ meson decays to D+π−, D0π+ and D∗+π− final states in pp collisions
A study of D+π−, D0π+ and D∗+π− final states is performed using pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected at a centre-of-mass energy of 7 TeV with the LHCb detector. The D1(2420)0 resonance is observed in the D∗+π− final state and the D∗2(2460) resonance is observed in the D+π−, D0π+ and D∗+π− final states. For both resonances, their properties and spin-parity assignments are obtained. In addition, two natural parity and two unnatural parity resonances are observed in the mass region between 2500 and 2800 MeV. Further structures in the region around 3000 MeV are observed in all the D∗+π−, D+π− and D0π+ final states
Measurement of the relative rate of prompt χc0, χc1 and χc2 production at √s=7TeV
Prompt production of charmonium χc0, χc1 and χc2 mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of √s=7TeV. The χc mesons are identified through their decay to J/ψγ, with J/ψ→μ+mu− using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of 1.0fb−1 collected by the LHCb detector, is used to measure the relative prompt production rate of χc1 and χc2 in the rapidity range 2.0<y<4.5 as a function of the J/ψ transverse momentum from 3 to 20 GeV/c. First evidence for χc0 meson production at a hadron collider is also presented
Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays
A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity
Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays
A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%
Observation of the decay
The decay is observed for the first
time, using proton-proton collisions collected with the LHCb detector
corresponding to an integrated luminosity of 3fb. A signal yield of
decays is reported with a significance of 6.2 standard deviations.
The ratio of the branching fraction of \B_c \rightarrow J/\psi K^+ K^- \pi^+
decays to that of decays is measured to be
, where the first uncertainty is statistical and the
second is systematic.Comment: 18 pages, 2 figure
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