571 research outputs found
Dual Antiplatelet Therapy Prior to Expedited Carotid Surgery Reduces Recurrent Events Prior to Surgery without Significantly Increasing Peri-operative Bleeding Complications
ObjectiveA daily Rapid-Access TIA Clinic was introduced in 2008, where symptomatic patients were started on 75 mg aspirin + 40 mg simvastatin by the referring doctor, before attending the clinic. Following clinic assessment, patients with 50–99% stenoses were transferred to the vascular unit for carotid endarterectomy (CEA). In two audits (n = 212 patients), the median delay from transfer to the vascular unit to undergoing CEA was 3 days, during which time 28 patients (13%) suffered recurrent neurological events. It was hypothesized that early introduction of dual antiplatelet therapy (by adding clopidogrel 75 mg once parenchymal haemorrhage was excluded in the TIA clinic) might significantly reduce recurrent events between transfer to the surgical unit and undergoing CEA.MethodsProspective audit in 100 consecutive, recently symptomatic patients receiving dual antiplatelet therapy. Endpoints were: prevalence of recurrent events between transfer from the TIA clinic and undergoing CEA; rates of spontaneous embolization prior to undergoing CEA; and prevalence of haemorrhagic complicationsResultsThe median delay from symptom to CEA was 8 days (IQR 5–15). The median delay between transfer from the TIA clinic to CEA was 3 days (IQR 2–5), during which time three patients (3%) suffered recurrent TIAs. This represents a fivefold reduction compared with previous audit data (OR 4.9, 95% CI 1.5–16.6, p = .01) and was matched by a fourfold reduction in the prevalence of spontaneous embolization from 39/189 (21%) previously to 5/83 (5%) in the current audit (OR 4.1, 95% CI 1.5–10.7, p = .0047). The 30-day death/stroke rate was 1%. There were three haemorrhagic complications: stroke caused by haemorrhagic transformation of an infarct; exploration for neck haematoma; and debridement and skin grafting for spontaneous shin haematoma.ConclusionEarly introduction of dual antiplatelet therapy was associated with a significant reduction in recurrent neurological events and spontaneous embolization prior to CEA, without incurring a significant increase in major peri-operative bleeding complications
All clinically relevant components, from prion infected blood donors, can cause disease following a single transfusion
Telecommunication wavelength GaAsBi light emitting diodes
GaAsBi light emitting diodes containing ∼6% Bi are grown on GaAs substrates. Good room-temperature electroluminescence spectra are obtained at current densities as low as 8 Acm − 2. Measurements of the integrated emitted luminescence suggest that there is a continuum of localised Bi states extending up to 75 meV into the bandgap, which is in good agreement with previous photoluminescence studies. X-ray diffraction analysis shows that strain relaxation has probably occurred in the thicker samples grown in this study
Dynamical modelling of the elliptical galaxy NGC 2974
In this paper we analyse the relations between a previously described oblate
Jaffe model for an ellipsoidal galaxy and the observed quantities for NGC 2974,
and obtain the length and velocity scales for a relevant elliptical galaxy
model. We then derive the finite total mass of the model from these scales, and
finally find a good fit of an isotropic oblate Jaffe model by using the
Gauss-Hermite fit parameters and the observed ellipticity of the galaxy NGC
2974. The model is also used to predict the total luminous mass of NGC 2974,
assuming that the influence of dark matter in this galaxy on the image,
ellipticity and Gauss-Hermite fit parameters of this galaxy is negligible
within the central region, of radius Comment: 7 figure
(Sub)mm Interferometry Applications in Star Formation Research
This contribution gives an overview about various applications of (sub)mm
interferometry in star formation research. The topics covered are molecular
outflows, accretion disks, fragmentation and chemical properties of low- and
high-mass star-forming regions. A short outlook on the capabilities of ALMA is
given as well.Comment: 20 pages, 7 figures, in proceedings to "2nd European School on Jets
from Young Star: High Angular Resolution Observations". A high-resolution
version of the paper can be found at
http://www.mpia.de/homes/beuther/papers.htm
Cohort studies of fat intake and the risk of breast cancer--a pooled analysis.
Cohort studies of fat intake and the risk of breast cancer--a pooled analysis. Hunter DJ, Spiegelman D, Adami HO, Beeson L, van den Brandt PA, Folsom AR, Fraser GE, Goldbohm RA, Graham S, Howe GR, et al. Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA. BACKGROUND. Experiments in animals, international correlation comparisons, and case-control studies support an association between dietary fat intake and the incidence of breast cancer. Most cohort studies do not corroborate the association, but they have been criticized for involving small numbers of cases, homogeneous fat intake, and measurement errors in estimates of fat intake. METHODS. We identified seven prospective studies in four countries that met specific criteria and analyzed the primary data in a standardized manner. Pooled estimates of the relation of fat intake to the risk of breast cancer were calculated, and data from study-specific validation studies were used to adjust the results for measurement error. RESULTS. Information about 4980 cases from studies including 337,819 women was available. When women in the highest quintile of energy-adjusted total fat intake were compared with women in the lowest quintile, the multivariate pooled relative risk of breast cancer was 1.05 (95 percent confidence interval, 0.94 to 1.16). Relative risks for saturated, monounsaturated, and polyunsaturated fat and for cholesterol, considered individually, were also close to unity. There was little overall association between the percentage of energy intake from fat and the risk of breast cancer, even among women whose energy intake from fat was less than 20 percent. Correcting for error in the measurement of nutrient intake did not materially alter these findings. CONCLUSIONS. We found no evidence of a positive association between total dietary fat intake and the risk of breast cancer. There was no reduction in risk even among women whose energy intake from fat was less than 20 percent of total energy intake. In the context of the Western lifestyle, lowering the total intake of fat in midlife is unlikely to reduce the risk of breast cancer substantially
Monte Carlo Methods for Estimating Interfacial Free Energies and Line Tensions
Excess contributions to the free energy due to interfaces occur for many
problems encountered in the statistical physics of condensed matter when
coexistence between different phases is possible (e.g. wetting phenomena,
nucleation, crystal growth, etc.). This article reviews two methods to estimate
both interfacial free energies and line tensions by Monte Carlo simulations of
simple models, (e.g. the Ising model, a symmetrical binary Lennard-Jones fluid
exhibiting a miscibility gap, and a simple Lennard-Jones fluid). One method is
based on thermodynamic integration. This method is useful to study flat and
inclined interfaces for Ising lattices, allowing also the estimation of line
tensions of three-phase contact lines, when the interfaces meet walls (where
"surface fields" may act). A generalization to off-lattice systems is described
as well.
The second method is based on the sampling of the order parameter
distribution of the system throughout the two-phase coexistence region of the
model. Both the interface free energies of flat interfaces and of (spherical or
cylindrical) droplets (or bubbles) can be estimated, including also systems
with walls, where sphere-cap shaped wall-attached droplets occur. The
curvature-dependence of the interfacial free energy is discussed, and estimates
for the line tensions are compared to results from the thermodynamic
integration method. Basic limitations of all these methods are critically
discussed, and an outlook on other approaches is given
Multidimensional Conservation Laws: Overview, Problems, and Perspective
Some of recent important developments are overviewed, several longstanding
open problems are discussed, and a perspective is presented for the
mathematical theory of multidimensional conservation laws. Some basic features
and phenomena of multidimensional hyperbolic conservation laws are revealed,
and some samples of multidimensional systems/models and related important
problems are presented and analyzed with emphasis on the prototypes that have
been solved or may be expected to be solved rigorously at least for some cases.
In particular, multidimensional steady supersonic problems and transonic
problems, shock reflection-diffraction problems, and related effective
nonlinear approaches are analyzed. A theory of divergence-measure vector fields
and related analytical frameworks for the analysis of entropy solutions are
discussed.Comment: 43 pages, 3 figure
Prevalence and risk factors for bovine leptospirosis in Mato Grosso do Sul, Brazil
Foi investigada a prevalência de anticorpos antileptospira em fêmeas bovinas com idade igual ou superior a 24 meses, provenientes de 178 rebanhos de 22 municípios do estado de Mato Grosso do Sul, bem como identificados fatores de risco associados à infecção. Foram analisadas 2.573 amostras de soro sangüíneo por meio do teste de soroaglutinação microscópica perante 10 sorovares de leptospira. Títulos iguais ou superiores a 100 para um ou mais sorovares foram detectados em 1.801 fêmeas (98,8%) de 161 (96,5%) rebanhos. O sorovar Hardjo (65,6%) foi apontado como o mais provável, seguido do sorovar Wolffi (12,3%). Os resultados demonstram que a leptospirose bovina se encontra presente em todos os municípios estudados, com alta prevalência, tanto em animais como em rebanhos. Os fatores de risco identificados neste estudo e associados à infecção por bactérias do gênero lepstopira foram o tipo de exploração pecuária de corte e a raça Zebu. _____________________________________________________________________________________________________________ ABSTRACTThe prevalence of anti-Leptospira spp. antibodies was estimated for female cattle aged 24 months or older. The sample comprised 178 herds from 22 counties in the state of Mato Grosso do Sul, Brazil. The risk factors associated with the presence of infeccion were investigated. A total of 2,573 blood serum samples were tested against 10 leptospira serovars using the microagglutination test (MAT). Titers of 100 or higher for one or more serovars were detected in 1,801 females (98.8%) from 161 herds (96.5%). Serovar Hardjo (65.6%) was the most frequent, followed by serovar Wolffi (12.3%). These results suggest that bovine leptospirosis is widespread in all the counties under study, with a high prevalence both at the animal and the herd level. Beef farms and the Zebu breed were associated to the higher risk of herd infection by leptospiras
Pooled analysis of prospective cohort studies on height, weight, and breast cancer risk
The association between anthropometric indices and the risk of breast cancer was analyzed using pooled data from seven prospective cohort studies. Together, these cohorts comprise 337,819 women and 4,385 incident invasive breast cancer cases. In multivariate analyses controlling for reproductive, dietary, and other risk factors, the pooled relative risk (RR) of breast cancer per height increment of 5 cm was 1.02 (95% confidence interval (Cl): 0.96, 1.10) in premenopausal women and 1.07 (95% Cl: 1.03, 1.12) in postmenopausal women. Body mass index (BMI) showed significant inverse and positive associations with breast cancer among pre- and postmenopausal women, respectively; these associations were nonlinear. Compared with premenopausal women with a BMI of less than 21 kg/m2, women with a BMI exceeding 31 kg/m2 had an RR of 0.54 (95% Cl: 0.34, 0.85). In postmenopausal women, the RRs did not increase further when BMI exceeded 28 kg/m2; the RR for these women was 1.26 (95% Cl: 1.09, 1.46). The authors found little evidence for interaction with other breast cancer risk factors. Their data indicate that height is an independent risk factor for postmenopausal breast cancer; in premenopausal women, this relation is less clear. The association between BMI and breast cancer varies by menopausal status. Weight control may reduce the risk among postmenopausal women
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