724 research outputs found
Functionally graded titanium implants: Characteristic enhancement induced by combined severe plastic deformation
Commercially pure titanium was processed by equal channel angular pressing (ECAP) and surface mechanical attrition treatment (SMAT) for the purpose of developing functionally graded titanium used for implants and a gradient structure including nanostructured, deformed and undeformed zones were produced on the samples. In particular, it was aimed to design the gradient-structure in the titanium with enhanced properties by applying 4 ECAP passes to form bulk structure of ultrafine-grains and subsequently subjecting SMAT to the surface of ECAPed samples to produce nanostructured surface region. Microstructural examination was made by electron back scatter diffraction (EBSD). Also, microhardness, nanoindentation, topography, roughness and wettability were evaluated. To examine the biological response, human osteosarcoma cells were cultured in contact with the samples in various time periods and morphology change, cell viability and alkaline phosphate activity were conducted also cell morphology was monitored. EBSD showed development of ultrafine-grained structure after 4 passes of ECAP with an average grain size of 500 nm. Applying SMAT resulted in additional refinement in the ECAP samples, particularly in the subsurface regions to a depth of 112 μm. Furthermore, the SMATed samples showed an enhancement in roughness, wettability and hardness magnitudes. Viability enhanced up to 7% in SMATed + ECAPed sample, although the acceptable cell adhesion, improved cell differentiation and mineralization were seen. The combined use of ECAP and SMAT has shown a good potential for optimizing the design of modern functionally graded medical devices and implants
Fast temporal dynamics and causal relevance of face processing in the human temporal cortex
We measured the fast temporal dynamics of face processing simultaneously across the human temporal cortex (TC) using intracranial recordings in eight participants. We found sites with selective responses to faces clustered in the ventral TC, which responded increasingly strongly to marine animal, bird, mammal, and human faces. Both face-selective and face-active but non-selective sites showed a posterior to anterior gradient in response time and selectivity. A sparse model focusing on information from the human face-selective sites performed as well as, or better than, anatomically distributed models when discriminating faces from non-faces stimuli. Additionally, we identified the posterior fusiform site (pFUS) as causally the most relevant node for inducing distortion of conscious face processing by direct electrical stimulation. These findings support anatomically discrete but temporally distributed response profiles in the human brain and provide a new common ground for unifying the seemingly contradictory modular and distributed modes of face processing
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Timing and Predictors of Recanalization After Anticoagulation in Cerebral Venous Thrombosis.
BACKGROUND AND PURPOSE
Vessel recanalization after cerebral venous thrombosis (CVT) is associated with favorable outcomes and lower mortality. Several studies examined the timing and predictors of recanalization after CVT with mixed results. We aimed to investigate predictors and timing of recanalization after CVT.
METHODS
We used data from the multicenter, international AntiCoagulaTION in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT) study of consecutive patients with CVT from January 2015 to December 2020. Our analysis included patients that had undergone repeat venous neuroimaging more than 30 days after initiation of anticoagulation treatment. Prespecified variables were included in univariate and multivariable analyses to identify independent predictors of failure to recanalize.
RESULTS
Among the 551 patients (mean age, 44.4±16.2 years, 66.2% women) that met inclusion criteria, 486 (88.2%) had complete or partial, and 65 (11.8%) had no recanalization. The median time to first follow-up imaging study was 110 days (interquartile range, 60-187). In multivariable analysis, older age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.03-1.07), male sex (OR, 0.44; 95% CI, 0.24-0.80), and lack of parenchymal changes on baseline imaging (OR, 0.53; 95% CI, 0.29-0.96) were associated with no recanalization. The majority of improvement in recanalization (71.1%) occurred before 3 months from initial diagnosis. A high percentage of complete recanalization (59.0%) took place within the first 3 months after CVT diagnosis.
CONCLUSION
Older age, male sex, and lack of parenchymal changes were associated with no recanalization after CVT. The majority recanalization occurred early in the disease course suggesting limited further recanalization with anticoagulation beyond 3 months. Large prospective studies are needed to confirm our findings
Evidence of a structure in (K)over-bar(0)Lambda(+)(c) consistent with a charged Xi(c)(2930)(+), and updated measurement of (B)over-bar(0) -> (K)over-bar(0)Lambda(+)(c) (Lambda)over-bar(c)(-) at Belle
We report evidence for the charged charmed-strange baryon Xi(c)(2930)(+) with a signal significance of 3.9 sigma with systematic errors included. The charged Xi(c)(2930)(+) is found in its decay to K-S(0)Lambda(+)(c) in the substructure of (B) over bar (0) -> K-S(0)Lambda(+)(c)(Lambda) over bar (-)(c) decays. The measured mass and width are [2942.3 +/- 4.4(stat.) +/- 1.5(syst.)] MeV/c(2) and [14.8 +/- 8.8(stat.) +/- 2.5(syst.)] MeV, respectively, and the product branching fraction is B((B) over bar (0) -> Xi(c)(2930)(+)(Lambda) over bar (-)(c)) B(Xi(c)(2930)(+) -> (K) over bar (0)(S)Lambda(+)(c)) = [2.37 +/- 0.51(stat.) +/- 0.31 (syst.)] x 10(-4). We also measure B((B) over bar (0) -> (K) over bar (0)(S)Lambda(+)(c)(Lambda) over bar (-)(c)) = [3.99 +/- 0.76(stat.) +/- 0.51(syst.)] x 10(-4) with greater precision than previous experiments, and present the results of a search for the charmonium-like state Y (4660) and its spin partner, Y-eta, in the Lambda(+)(c)(Lambda) over bar (-)(c) invariant mass spectrum. No clear signals of the Y (4660) or Y-eta are observed and the 90% credibility level (C.L.) upper limits on their production rates are determined. Thesemeasurements are obtained from a sample of (772 +/- 11) x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance by the Belle detector at the KEKB asymmetric energy electron-positron collider
Measurement of the CKM Matrix Element from at Belle
We present a new measurement of the CKM matrix element from decays, reconstructed with the full Belle data set
of integrated luminosity. Two form factor
parameterizations, originally conceived by the Caprini-Lellouch-Neubert (CLN)
and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product
and the decay form factors, where
is the normalization factor and is a small
electroweak correction. In the CLN parameterization we find
, , , . For the BGL parameterization we
obtain , which is consistent with the World Average when correcting for
. The branching fraction of is measured to be . We also present a new
test of lepton flavor universality violation in semileptonic decays,
. The errors correspond to the statistical and
systematic uncertainties respectively. This is the most precise measurement of
and form factors to date and the first
experimental study of the BGL form factor parameterization in an experimental
measurement
Measurement of the lepton polarization and in the decay with one-prong hadronic decays at Belle
With the full data sample of pairs recorded by
the Belle detector at the KEKB electron-positron collider, the decay is studied with the hadronic
decays and . The polarization in two-body hadronic
decays is measured, as well as the ratio of the branching fractions , where
denotes an electron or a muon. Our results, and , are consistent with the theoretical
predictions of the Standard Model. The polarization values of are excluded at the 90\% confidence level.Comment: 17 pages, 11 figures, submitted to Physical Review
Search for violation in the decay at Belle
We search for violation in the charged charm meson decay
, based on a data sample corresponding to an integrated
luminosity of collected by the Belle experiment at the KEKB
asymmetric-energy collider. The measured violating asymmetry
is , which is consistent with
the standard model prediction and has a significantly improved precision
compared to previous results.Comment: 8 pages, 3 figure
Measurement of eta_c(1S), eta_c(2S) and non-resonant eta' pi+ pi- production via two-photon collisions
We report the measurement of gamma gamma to eta_c(1S), eta_c(2S) to eta' pi+
pi- with eta' decays to gamma rho and eta pi+ pi- using 941 fb^{-1} of data
collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.
The eta_c(1S) mass and width are measured to be M = [2984.6\pm0.7 (stat.)\pm2.2
(syst.)] MeV/c^{2} and \Gamma = [30.8^{+2.3}_{-2.2}~(stat.) \pm 2.5~(syst.)]
MeV, respectively. First observation of eta_c(2S) to eta' pi+ pi- with a
significance of 5.5sigma including systematic error is obtained, and the
eta_c(2S) mass is measured to be M = [3635.1\pm3.7~(stat.)\pm2.9~(syst.)]
MeV/c^{2}. The products of the two-photon decay width and branching fraction
(B) of decays to eta'pi+ pi- are determined to be \Gamma_{gamma gamma}B =
[65.4\pm2.6~(stat.)\pm6.9~(syst.)] eV for eta_c(1S) and
[5.6^{+1.2}_{-1.1}~(stat.)\pm1.1~(syst.)] eV for eta_c(2S). A new decay mode
for the eta_c(1S) to eta'f_0(2080) with f_0(2080) to pi+ pi- is observed with a
statistical significance of 20sigma. The f_0(2080) mass and width are
determined to be M = [2083^{+63}_{-66}~(stat.)\pm 32~(syst.)] MeV/c^{2} and
\Gamma = [178^{+60}_{-178}~(stat.) \pm 55~(syst.)] MeV. The cross sections for
gamma gamma to eta' pi+ pi- and eta'f_{2}(1270) are measured for the first
time.Comment: 19 pages, 14 figure
Observation of an alternative candidate in
We perform a full amplitude analysis of the process , where refers to either or . A new
charmoniumlike state that decays to is observed with a
significance of . Its mass is ()
MeV/ and width is () MeV. The
hypothesis is favored over the hypothesis at the level
of . The analysis is based on the 980 data sample
collected by the Belle detector at the asymmetric-energy collider
KEKB.Comment: 17 pages, 11 figure
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