98 resultados para Landau and Kolmogoroff type inequalities
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BACKGROUND: The role of statin therapy in heart failure (HF) is unclear. The amino-terminal propeptide of procollagen type III (PIIINP) predicts outcome in HF, and yet there are conflicting reports of statin therapy effects on PIIINP.
OBJECTIVES: This study determined whether there was an increase in serum markers of inflammation, fibrosis (including PIIINP), and B-type natriuretic peptide (BNP) in patients with systolic HF and normal total cholesterol and determined the effects of long-term treatment with atorvastatin on these markers.
METHODS: Fifty-six white patients with systolic HF and normal cholesterol levels (age 72 [13] years; 68% male; body mass index 27.0 [7.3] kg/m(2); ejection fraction 35 [13]%; 46% with history of smoking) were randomly allocated to atorvastatin treatment for 6 months, titrated to 40 mg/d (A group) or not (C group). Age- and/or sex-matched subjects without HF (N group) were also recruited. Biomarkers were measured at baseline (all groups) and 6 months (A and C groups).
RESULTS: Serum markers of collagen turnover, inflammation, and BNP were significantly elevated in HF patients compared with normal participants (all P < 0.05). There were correlations between these markers in HF patients but not in normal subjects. Atorvastatin treatment for 6 months caused a significant reduction in the following biomarkers compared with baseline: BNP, from median (interquartile range) 268 (190-441) pg/mL to 185 (144-344) pg/mL; high-sensitivity C-reactive protein (hs-CRP), from 5.26 (1.95 -9.29) mg/L to 3.70 (2.34-6.81) mg/L; and PIIINP, from 4.65 (1.86) to 4.09 (1.25) pg/mL (all P < 0.05 baseline vs 6 months). Between-group differences were significant for PIIINP only (P = 0.027). There was a positive interaction between atorvastatin effects and baseline hs-CRP and PIIINP (P < 0.01).
CONCLUSIONS: Long-term statin therapy reduced PIIINP in this small, selected HF population with elevated baseline levels. Further evaluation of statin therapy in the management of HF patients with elevated PIIINP is warranted.
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A matrix-type silicone elastomer vaginal ring providing 28-day continuous release of dapivirine (DPV) - a lead candidate human immunodeficiency virus type 1 (HIV-1) microbicide compound - has recently demonstrated moderate levels of protection in two Phase III clinical studies. Here, next-generation matrix and reservoir-type silicone elastomer vaginal rings are reported for the first time offering simultaneous and continuous in vitro release of DPV and the contraceptive progestin levonorgestrel (LNG) over a period of between 60 and 180days. For matrix-type vaginal rings comprising initial drug loadings of 100, 150 or 200mg DPV and 0, 16 or 32mg LNG, Day 1 daily DPV release values were between 4132 and 6113μg while Day 60 values ranged from 284 to 454μg. Daily LNG release ranged from 129 to 684μg on Day 1 and 2-91μg on Day 60. Core-type rings comprising one or two drug-loaded cores provided extended duration of in vitro release out to 180days, and maintained daily drug release rates within much narrower windows (either 75-131μg/day or 37-66μg/day for DPV, and either 96-150μg/day or 37-57μg/day for LNG, depending on core ring configuration and ignoring initial lag release effect for LNG) compared with matrix-type rings. The data support the continued development of these devices as multi-purpose prevention technologies (MPTs) for HIV prevention and long-acting contraception.
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Present work examines numerically the asymmetric behavior of hydrogen/air flame in a micro-channel subjected to a non-uniform wall temperature distribution. A high resolution (with cell size of 25 μm × 25 μm) of two-dimensional transient Navier–Stokes simulation is conducted in the low-Mach number formulation using detailed chemistry evolving 9 chemical species and 21 elementary reactions. Firstly, effects of hydrodynamic and diffusive-thermal instabilities are studied by performing the computations for different Lewis numbers. Then, the effects of preferential diffusion of heat and mass transfer on the asymmetric behavior of the hydrogen flame are analyzed for different inlet velocities and equivalence ratios. Results show that for the flames in micro-channels, interactions between thermal diffusion and molecular diffusion play major role in evolution of a symmetric flame into an asymmetric one. Furthermore, the role of Darrieus–Landau instability found to be minor. It is also found that in symmetric flames, the Lewis number decreases behind the flame front. This is related to the curvature of flame which leads to the inclination of thermal and mass fluxes. The mass diffusion vectors point toward the walls and the thermal diffusion vectors point toward the centerline. Asymmetric flame is observed when the length of flame front is about 1.1–1.15 times of the channel width.
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We present an analysis of interstellar NaI (lambda(air) = 3302.37 and 3302.98 angstrom), TiII (lambda(air) = 3383.76 angstrom) and CaII K (lambda(air) = 3933.66 angstrom) absorption features for 74 sightlines towards O- and B-type stars in the Galactic disc. The data were obtained from the Ultraviolet and Visual Echelle Spectrograph Paranal Observatory Project, at a spectral resolution of 3.75 km s(-1) and with mean signal-to-noise ratios per pixel of 260, 300 and 430 for the NaI, TiII and CaII observations, respectively. Interstellar features were detected in all but one of the TiII sightlines and all of the CaII sightlines. The dependence of the column density of these three species with distance, height relative to the Galactic plane, HI column density, reddening and depletion relative to the solar abundance has been investigated. We also examine the accuracy of using the NaI column density as an indicator of that for HI. In general, we find similar strong correlations for both Ti and Ca, and weaker correlations for Na. Our results confirm the general belief that Ti and Ca occur in the same regions of the interstellar medium ( ISM) and also that the TiII/CaII ratio is constant over all parameters. We hence conclude that the absorption properties of Ti and Ca are essentially constant under the general ISM conditions of the Galactic disc.
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Rabbit urethral smooth muscle cells were studied at 37 degrees C by using the amphotericin B perforated-patch configuration of the patch-clamp technique, using Cs(+)-rich pipette solutions. Two components of current, with electrophysiological and pharmacological properties typical of T- and L-type Ca(2+) currents, were recorded. Fitting steady-state inactivation curves for the L current with a Boltzmann equation yielded a V(1/2) of -41 +/- 3 mV. In contrast, the T current inactivated with a V(1/2) of -76 +/- 2 mV. The L currents were reduced by nifedipine (IC(50) = 225 +/- 84 nM), Ni(2+) (IC(50) = 324 +/- 74 microM), and mibefradil (IC(50) = 2.6 +/- 1.1 microM) but were enhanced when external Ca(2+) was substituted with Ba(2+). The T current was little affected by nifedipine at concentrations
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Background and purpose: W/Wv and wild-type murine bladders were studied to determine whether the W/Wv phenotype, which causes a reduction in, but not abolition of, tyrosine kinase activity, is a useful tool to study the function of bladder interstitial cells of Cajal (ICC).
Experimental approach: Immunohistochemistry, tension recordings and microelectrode recordings of membrane potential were performed on wild-type and mutant bladders.
Key results: Wild-type and W/Wv detrusors contained c-Kit- and vimentin-immunopositive cells in comparable quantities, distribution and morphology. Electrical field stimulation evoked tetrodotoxin-sensitive contractions in wild-type and W/Wv detrusor strips. Atropine reduced wild-type responses by 50% whereas a 25% reduction occurred in W/Wv strips. The atropine-insensitive component was blocked by pyridoxal-5-phosphate-6-azophenyl-2',4'-disulphonic acid in both tissue types. Wild-type and W/Wv detrusors had similar resting membrane potentials of -48 mV. Spontaneous electrical activity in both tissue types comprised action potentials and unitary potentials. Action potentials were nifedipine-sensitive whereas unitary potentials were not. Excitatory junction potentials were evoked by single pulses in both tissues. These were reduced by atropine in wild-type tissues but not in W/Wv preparations. The atropine-insensitive component was abolished by pyridoxal-5-phosphate-6-azophenyl-2',4'-disulphonic acid in both preparations.
Conclusions and implications: Bladders from W/Wv mice contain c-Kit- and vimentin-immunopositive ICC. There are similarities in the electrical and contractile properties of W/Wv and wild-type detrusors. However, significant differences were found in the pharmacology of the responses to neurogenic stimulation with an apparent up-regulation of the purinergic component. These findings indicate that the W/Wv strain may not be the best model to study ICC function in the bladder.
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We have developed a novel Multilocus Sequence Typing Scheme (MLST) and database (http://pubmlst.org/pacnes/) for Propionibacterium acnes based on the analysis of seven core housekeeping genes. The scheme, which was validated against previously described antibody, single locus and Random Amplification of Polymorphic DNA (RAPD) typing methods, displayed excellent resolution and differentiated 123 isolates into 37 sequence types (ST). An overall clonal population structure was detected with six eBURST groups representing the major clades I, II and III, along with two singletons. Two highly successful and global clonal lineages, ST6 (type IA) and ST10 (type IB1), representing 65% of this current MLST isolate collection were identified. The ST6 clone and closely related single locus variants (SLV), which comprise a large clonal complex CC6, dominated isolates from patients with acne, and were also significantly associated with ophthalmic infections. Our data therefore supports an association between acne and P. acnes strains from the type IA cluster and highlights the role of a widely disseminated clonal genotype in this condition. Characterisation of type I cell surface-associated antigens that are not detected in ST10 or strains of type II and III identified two dermatan-sulphate-binding proteins with putative phase/antigenic variation signatures. We propose that the expression of these proteins by type IA organisms contributes to their role in the pathophysiology of acne and helps explain the recurrent nature of the disease. The MLST scheme and database described in this study should provide a valuable platform for future epidemiological and evolutionary studies of P. acnes.
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UVES interstellar observations from the Paranal Observatory Project are presented for early-type stars located in the line of sight to the nearby open clusters IC 2391 (Omni Vel) and NGC 6475 (M7), with spectroscopic resolution R similar to 80 000 and signal-to-noise ratios in the Ti II (3383 angstrom), Ca II K, CH+ (4232 angstrom), Na I D and K I (7698 angstrom) lines of several hundred. The sightlines are a mixture of cluster and non-cluster objects. A total of 22 early-type stars (A and B type) are present in our sample towards IC 2391, with 21 towards NGC 6475/M7, and enable us to probe for differences in column density on scales from similar to 0.07 to 7.3 and similar to 0.05 to 4.9 pc in the respective clusters. Additionally, towards Praesepe the Na I D interstellar variation only is probed towards 13 sightlines and transverse scales of similar to 0.16-10.7 pc at R = 70 000. Towards IC 2391 variations are found in Ti II, Ca II K and Na I D column density in different sightlines of up to 0.7, 1.0 and 1.8 dex (excluding one star), respectively. This kind of variability correlates well with the Hipparcos parallax of the objects, and probes structure within the Local Bubble. For cluster-only objects the variations are 0.3, 0.3 and 0.5 dex, respectively. For the field of view towards NGC6475 the corresponding maximum variations are somewhat smaller, being 0.5, 0.3, 0.8 and 1.0 dex for Ti II, Ca II K, Na I and K I, respectively, for all objects and 0.4, 0.2, 0.6 and 0.7 dex for the cluster-only objects. These are uncorrelated with parallax, and again demonstrate that Ca II K tends to be more smoothly distributed than Na I D. A few likely cluster sightlines show evidence for CH+ and variations in this molecular species of a factor of 10 in equivalent width over sub-pc scales. Towards Praesepe variation in interstellar Na I D is small, being a maximum of only similar to 0.4 dex (including measurement errors), but with fewer sightlines studied. Overall, the scatter in the data is similar for the singly ionized species Ti II and Ca II, lending more support to the hypothesis that these two species sample similar parts of the interstellar medium (ISM). This also appears to be the case for the neutral species Na I D and K I in the one cluster studied. Finally, multiple-epoch observations from a variety of archive sources are used to search for astronomical unit (au) scale structure in the ISM towards 46 sightlines. There are tentative indications of structure on scales of tens to thousands of au for three sightlines. Future observations will confirm the veracity or otherwise of the time-variable components and others presented.
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OBJECTIVE: To investigate if there is a reduced risk of type 1 diabetes in children breastfed or exclusively breastfed by performing a pooled analysis with adjustment for recognized confounders.
RESEARCH DESIGN AND METHODS: Relevant studies were identified from literature searches using MEDLINE, Web of Science, and EMBASE. Authors of relevant studies were asked to provide individual participant data or conduct prespecified analyses. Meta-analysis techniques were used to combine odds ratios (ORs) and investigate heterogeneity between studies.
RESULTS: Data were available from 43 studies including 9,874 patients with type 1 diabetes. Overall, there was a reduction in the risk of diabetes after exclusive breast-feeding for >2 weeks (20 studies; OR = 0.75, 95% CI 0.64-0.88), the association after exclusive breast-feeding for >3 months was weaker (30 studies; OR = 0.87, 95% CI 0.75-1.00), and no association was observed after (nonexclusive) breast-feeding for >2 weeks (28 studies; OR = 0.93, 95% CI 0.81-1.07) or >3 months (29 studies; OR = 0.88, 95% CI 0.78-1.00). These associations were all subject to marked heterogeneity (I(2) = 58, 76, 54, and 68%, respectively). In studies with lower risk of bias, the reduced risk after exclusive breast-feeding for >2 weeks remained (12 studies; OR = 0.86, 95% CI 0.75-0.99), and heterogeneity was reduced (I(2) = 0%). Adjustments for potential confounders altered these estimates very little.
CONCLUSIONS: The pooled analysis suggests weak protective associations between exclusive breast-feeding and type 1 diabetes risk. However, these findings are difficult to interpret because of the marked variation in effect and possible biases (particularly recall bias) inherent in the included studies.
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High spectral resolution (~80 000) and signal-to-noise observations from the Ultraviolet and Visual Echelle Spectrograph Paranal Observatory Project (UVES-POP) are used to study the interstellarmolecular lines CN (3874 Å), CH+ (3957, 4232 Å) and CH (3886, 4300 Å) towards 74 O- and B-type stellar sightlines. Additionally, archive data are presented for 140 ELODIE early-type stellar sightlines at R = 42 000, plus 25 FEROS at R = 48 000 and 3 UVES at R > 50 000, mainly in the CH+ (4232 Å) and CH (3886, 4300 Å) transitions. Detection rates are ~45 per cent for CN and ~67 per cent for the other lines in the POP sample, and ~10-15 per cent for CH+ and CH lines in the additional sample. CH and CH+ are well correlated between log[N(CH) cm-2]~12-14, implying that these clouds are CH+-like CH and not CN-like CH. CH is also very well correlated with Na I D in the range log[N(Na I cm-2]) ~12.2-14.2. A few sightlines show tentative velocity shifts of ~2 km s-1 between CH and CH+, which appear to be caused by differences in component strength in blends, and hence do not provide firm evidence for shocks. Finally, we describe a search for 13CH+ in a sightline towards HD 76341. No 13CH+ is detected, placing a limit on the 13CH+ to 12CH+ ratio of ~0.01. If a formal fit is attempted, the equivalent width ratio in the two isotopes is a factor ~90 but with large errors.
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We report on our serendipitous pre-discovery detection and follow-up observations of the broad-lined Type Ic supernova (SN Ic) 2010ay at z = 0.067 imaged by the Pan-STARRS1 3π survey just ~4 days after explosion. The supernova (SN) had a peak luminosity, MR ≈ -20.2 mag, significantly more luminous than known GRB-SNe and one of the most luminous SNe Ib/c ever discovered. The absorption velocity of SN 2010ay is v Si ≈ 19 × 103 km s-1 at ~40 days after explosion, 2-5 times higher than other broad-lined SNe and similar to the GRB-SN 2010bh at comparable epochs. Moreover, the velocity declines ~2 times slower than other SNe Ic-BL and GRB-SNe. Assuming that the optical emission is powered by radioactive decay, the peak magnitude implies the synthesis of an unusually large mass of 56Ni, M Ni = 0.9 M ⊙. Applying scaling relations to the light curve, we estimate a total ejecta mass, M ej ≈ 4.7 M ⊙, and total kinetic energy, EK ≈ 11 × 1051 erg. The ratio of M Ni to M ej is ~2 times as large for SN 2010ay as typical GRB-SNe and may suggest an additional energy reservoir. The metallicity (log (O/H)PP04 + 12 = 8.19) of the explosion site within the host galaxy places SN 2010ay in the low-metallicity regime populated by GRB-SNe, and ~0.5(0.2) dex lower than that typically measured for the host environments of normal (broad-lined) SNe Ic. We constrain any gamma-ray emission with E γ ~ 1048 erg. We therefore rule out the association of a relativistic outflow like those that accompanied SN 1998bw and traditional long-duration gamma-ray bursts (GRBs), but we place less-stringent constraints on a weak afterglow like that seen from XRF 060218. If this SN did not harbor a GRB, these observations challenge the importance of progenitor metallicity for the production of relativistic ejecta and suggest that other parameters also play a key role.
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The in vitro release characteristics of eight low-molecular-weight drugs (clindamycin, 17beta-estradiol, 17beta-estradiol-3-acetate, 17beta-estradiol diacetate, metronidazole, norethisterone, norethisterone acetate and oxybutynin) from silicone matrixtype intravaginal rings of various drug loadings have been evaluated under sink conditions. Through modelling of the release data using the Higuchi equation, and determination of the silicone solubility of the drugs, the apparent silicone elastomer diffusion coefficients of the drugs have been calculated. Furthermore, in an attempt to develop a quantitative model for predicting release rates of new drug substances from these vaginal ring devices, it has been observed that linear relationships exist between the log of the silicone solubility of the drug (mg ml(-1)) and the reciprocal of its melting point (K-1) (y = 3.558x - 9.620, R = 0.77), and also between the log of the diffusion coefficient (cm(2) s(-1)) and the molecular weight of the drug molecule (g mol(-1)) (y = - 0.0068x - 4.0738, R = 0.95). Given that the silicone solubility and silicone diffusion coefficient are the major parameters influencing the permeation of drugs through silicone elastomers, it is now possible to predict through use of the appropriate mathematical equations both matrix-type and reservoir-type intravaginal ring release rates simply from a knowledge of drug melting temperature and molecular weight. (C) 2003 Elsevier Science B.V. All rights reserved.
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What role do elections play in societies emerging from communal war and what type of institutions can serve as catalysts in deepening peace and compromise? While some analysts argue that ethnicity should be recognized through 'consociational' institutions, others maintain that 'integrative' devices - in particular, carefully crafted electoral rules - can limit or even break down the salience of ethnicity and increase the possibility for inter-ethnic accommodation. This article examines the post-war electoral experience of Bosnia and Herzegovina (BiH), arguing that elections had a problematic, unintended impact on peacebuilding. First, timid integrative electoral devices were adopted in a consociational system that reifies ethnic division and complicates compromise; second, peacebuilding agencies needlessly manufactured electoral rules that backfired; third, group-based features of the BiH political system run counter to individual human rights. The article ends with suggestions for improving the electoral framework.