169,730 research outputs found
Carleson measures for the Drury–Arveson Hardy space and other Besov–Sobolev spaces on complex balls
No full textAbstractFor 0⩽σ<1/2 we characterize Carleson measures μ for the analytic Besov–Sobolev spaces B2σ on the unit ball Bn in Cn by the discrete tree condition∑β⩾α[2σd(β)I*μ(β)]2⩽CI*μ(α)<∞,α∈Tn, on the associated Bergman tree Tn. Combined with recent results about interpolating sequences this leads, for this range of σ, to a characterization of universal interpolating sequences for B2σ and also for its multiplier algebra.However, the tree condition is not necessary for a measure to be a Carleson measure for the Drury–Arveson Hardy space Hn2=B21/2. We show that μ is a Carleson measure for B21/2 if and only if both the simple condition2d(α)I*μ(α)⩽C,α∈Tn, and the split tree condition∑k⩾0∑γ⩾α2d(γ)−k∑(δ,δ′)∈G(k)(γ)I*μ(δ)I*μ(δ′)⩽CI*μ(α),α∈Tn, hold. This gives a sharp estimate for Drury's generalization of von Neumann's operator inequality to the complex ball, and also provides a universal characterization of Carleson measures, up to dimensional constants, for Hilbert spaces with a complete continuous Nevanlinna–Pick kernel function.We give a detailed analysis of the split tree condition for measures supported on embedded two manifolds and we find that in some generic cases the condition simplifies. We also establish a connection between function spaces on embedded two manifolds and Hardy spaces of plane domains
Markers of coronary damage. From diagnosis to prognosis
No full textCardiovascular disease is a major public health problem, Rapid and accurate diagnosis in the
emergency department is essential for timely initiation oftreatment, thus any means for improving
the speed and accuracy of acute coronary syndrome (ACS) diagnosis can contribute to better
clinical and economi c outcomes. Measurement of circulating level of troponin has proven to be a
sensitive and specific test for cardiac damage detection but they do not discriminate between
ischemic and not ischemic etiologies of'rnyocardial injury. Combining troponin with other cardiac
biomarkers may offer complimentary information on the underlying pathobiology and prognosis in
an individual patient, may increase the analytic sensitivity for myocardial damage and offer insights
into the timing and mechanism of myocardial injury. Several prospective epidemiological studies
have documented an association between inflammatory markers and cardiovascular disease and
their role in primary and secondary prevention and as predictor of mortality. OBJECTIVE: We
sought to report a selected but representative evidence on some new biological markers of cardiac
damage, ineluding inflammatory cytokines in patients with cardiovascular disease. DATA
SOURCES: We searched in Medline from January 1998 to March 2005 for all studies focusing on
the diagnostic and prognostic value of new markers of cardiac damage in patients with ACS and
heart failure. CONCLUSION: The use ofnecrotic markers to risk stratify patients with chest pain
has become an established practice in the clinical setting while the role of other inflammatory
biomarkers, despite being still undefined, seems promising under both pathophysiologic and
prognostic perspective
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
The control of catalytic performance of rutile-type Sn/V/Nb/Sb mixed oxides, catalysts for propane ammoxidation to acrylonitrile
No full textArcozzi, Elena Ballarini, Nicola Cavani, Fabrizio Cimini, Massimo Lucarelli, Carlo Trifiro, Ferruccio Delichere, Pierre Millet, Jean-Marc M. Marion, PhilippeInternational audienceThis paper describes the effect of the composition of rutile-type Sn/V/Nb/Sb mixed oxides catalysts on the catalytic performance in the gas-phase ammoxidation of propane to acrylonitrile. The variation in the atomic ratio between components in catalysts is the key for the control of activity and selectivity. In samples with atomic composition Sn/V/Nb/Sb 1/0.2/1/x (0 <= x <= 5) and 1/0.2/y/3 (0 <= y <= 3) several compounds formed, i.e., SnO2, Sb/Nb mixed oxide, Sb6O13 and non-stoichiometric rutile-type V/Nb/Sb/O; the latter segregated preferentially at the surface of the catalyst. Tin oxide provided the rutile matrix for the dispersion of the mixed oxides. The main role of Sb was shown to generate mixed oxides containing specific sites for the allylic ammoxidation of propylene intermediately formed. The presence of Nb enhanced the activity and selectivity of these sites. (C) 2008 Elsevier B.V. All rights reserved
The 5-Year Clinical Outcomes After a Randomized Comparison of Sirolimus-Eluting Versus Bare-Metal Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction
No full textBecause patients with acute ST-segment elevation
myocardial infarction (STEMI) were excluded from early randomized
trials, only relatively short-term data from large multicenter studies
comparing drug-eluting stents (DES) with bare-metal stents (BMS) are
currently available. Unambiguous ascertainment of long-term compliance
with thienopyridines is problematic in STEMI, which is a matter of
serious concern (1,2), and one observational registry suggested higher late
(6 months) unadjusted and adjusted mortality rates in STEMI patients
with a DES compared with those with a BMS (3). Thus, the use of a
DES in STEMI patients still remains highly controversial.
The design of the study and outcomes at 8- and 24-month
follow-up were previously reported (4,5). Since then, all eligible
patients underwent routine clinical follow-up at 6-month intervals for
5 years after index intervention. All events up to 5 years were
adjudicated by an independent clinical event committee that was
blinded to the treatment assignments.
All analyses were conducted according to the intent-to-treat
principle. Event-free survival curves were generated using the Kaplan-
Meier method, and survival between groups was compared using the
log-rank test. Hazard ratios (HRs) with 95% confidence intervals
(CIs) were calculated using the Cox proportional hazards model.
The cumulative duration of dual antiplatelet treatment trended
longer in the tirofiban–sirolimus-eluting stent (SES) arm (182 92
days vs. 155 105 days in the abciximab BMS group; p 0.073);
however, 80% and 100% of patients in both groups discontinued
thienopyridines after 250 days and 360 days, respectively. Overall, use
of medications did not differ between study groups at any time point
during follow-up. Complete follow-up information for as long as
1,800 days was available for all patients.
At 5 years, the cumulative incidence of major adverse cardiac
events (MACE) (death, myocardial infarction [MI], or target
vessel revascularization) trended lower in the tirofiban-SES group
(29.9% vs. 43.2%; HR: 0.63 [95% CI: 0.39 to 1.03]; p 0.067)
(Fig. 1A). All-cause mortality (18.4%; 95% CI: 12% to 28%) (Fig.
1A) and the composite of death or MI (21.8%; 95% CI: 14% to 32%)
(Fig. 1B) were similar in the tirofiban-SES versus the abciximab-
BMS group (15.9%; 95% CI: 10% to 25%, p 0.70 and 25.0%; 95%
CI: 17% to 35%, p 0.58, respectively), whereas the need for target
vessel revascularization remained markedly reduced (10.3% vs. 26.1%;
HR: 0.37 [95% CI: 0.17 to 0.79]; p 0.007) in the tirofiban-SES
group (Fig. 1C).
The cumulative incidence of definite, probable, or possible stent
thrombosis was 6.9% versus 7.9% in the tirofiban-SES group and
abciximab-BMS group, respectively (HR: 0.86 [95% CI: 0.29 to 2.6];
p 0.78 (Fig. 1B). The cumulative incidence of definite and definite
or probable stent thrombosis also did not differ between the 2 groups.
Among patients who were alive at 12 months, the cumulative
incidence of death or nonfatal MI at 5 years was 11.2% in the
tirofiban-SES group and 10% in the abciximab-BMS group (p
0.80 at log-rank test). Finally, excluding patients who underwent
target vessel revascularization between 30 days and 1 year after the
index procedure, the cumulative incidence of death or nonfatal MI at
5 years was 21.5% in the tirofiban-SES and 24.7% in the abciximab-
BMS group (p 0.78 at log-rank test), whereas the incidence of
death or nonfatal MI at 5 years in patients who survived the first year
follow-up free from target vessel revascularization was 9.7% in the
tirofiban-SES group and 9.2% in the abciximab-BMS group (p
0.88; log-rank test).
Although it was open label and single center, our study is the
first randomized controlled investigation of DES versus BMS
implantation in the setting of STEMI patients undergoing mechanical
intervention.
A maintained clinical benefit for 24 months in terms of
reintervention in the previously instrumented artery with no excess
of subacute or late stent thrombosis was previously reported (5,6).
The current report extends these findings to 5-year follow-up.
Although results from randomized controlled trials are still pending
(7), expert consensus recommends prolonging treatment with
aspirin and thienopyridines for at least 1 year after DES placement.
Importantly, our study was conceived and conducted well before
unambiguous safety issues for DES use were raised. As a consequence,
only relatively short duration of dual antiplatelet treatment (i.e., a
minimum of 3 months) was protocol mandated. Accordingly, approximately
one-half of the patients discontinued thienopyridines by 6
months after intervention and nearly all discontinued dual antiplatelet
treatment at 1 year. Thus, long-term follow-up of this study is critical
to shed light on the safety profile of SES implantation followed by a
relatively short combined antiplatelet regimen in unselected patients
undergoing intervention for STEMI, a currently off-label indication.
At 5-year follow-up, the cumulative incidence of death or nonfatal
MI remained similar in the 2 study groups, and this held true at
landmark analysis of patients alive at 12-month follow-up. Based on
a broad clinical definition of stent thrombosis, namely, the Academic
Research Consortium classification, we likewise failed to observe an
excess of late events in those patients assigned to receive SES
implantation, whereas the benefit in terms of reintervention persisted
almost unchanged after 1,800 days with no evidence of a late catch-up
phenomenon. This is in keeping with the long-term results of the
landmark randomized studies that led to DES approval, whereas it
contrasts with recent data from observational studies on acute MI
patients that questioned the long-term durability of DES benefit in
this patient/lesion subset (3,8)
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Effect of thienopyridines discontinuation on mortality or MI after SES versus BMS implantation in STEMI
No full textA Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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