4,048 research outputs found
Alternative antibody for the detection of CA19-9 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access (R) GI Monitor assay on the UniCel (R) Dxl 800 Immunoassay System
Background: Gastrointestinal cancer antigen CA19-9 is known as a valuable marker for the management of patients with pancreatic cancer. Methods: The analytical and clinical performance of the Access(R) GI Monitor assay (Beckman Coulter) was evaluated on the UniCel(R) Dxl 800 Immunoassay System at five different European sites and compared with a reference method, defined as CA19-9 on the Elecsys System (Roche Diagnostics). Results: Total imprecision (%CV) of the GI Monitor ranged between 3.4% and 7.7%, and inter-laboratory reproducibility between 3.6% and 4.0%. Linearity upon dilution showed a mean recovery of 97.4% (SD+7.2%). Endogenous interferents had no influence on GI Monitor levels (mean recoveries: hemoglobin 103%, bilirubin 106%, triglycerides 106%). There was no high-dose hook effect up to 115,000 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access' GI Monitor and Elecsys CA19-9 (R = 0.959, slope = 1.004, intercept +0.17). GI Monitor serum levels were low in healthy individuals (n = 267, median = 6.0 kU/L, 95th percentile = 23.1 kU/L), higher in individuals with various benign diseases (n = 550, medians = 5.8-13.4 kU/L, 95th percentiles = 30.1-195.5 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 8.4-233.8 kU/L, 95th percentiles = 53.7-13,902 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the GI Monitor was found for pancreatic cancer {[}area under the curve (AUC) 0.83]. Results for the reference CA19-9 assay were comparable (AUC 0.85). Conclusions: The Access(R) GI Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with the Elecsys CA19-9. The GI Monitor shows the best diagnostic accuracy in pancreatic cancer. Our results also suggest a clinical value of the GI Monitor in other cancers
Implementation of the LDA+U method using the full potential linearized augmented plane wave basis
We provide a straightforward and efficient procedure to combine LDA+U total
energy functional with the full potential linearized augmented plane wave
method. A detailed derivation of the LDA+U Kohn-Sham type equations is
presented for the augmented plane wave basis set, and a simple
``second-variation'' based procedure for self-consistent LDA+U calculations is
given. The method is applied to calculate electronic structure and magnetic
properties of NiO and Gd. The magnetic moments and band eigenvalues obtained
are in very good quantitative agreement with previous full potential LMTO
calculations. We point out that LDA+U reduces the total d charge on Ni by 0.1
in NiO
Coronal heating distribution due to low-frequency wave-driven turbulence
The heating of the lower solar corona is examined using numerical simulations
and theoretical models of magnetohydrodynamic turbulence in open magnetic
regions. A turbulent energy cascade to small length scales perpendicular to the
mean magnetic field can be sustained by driving with low-frequency Alfven waves
reflected from mean density and magnetic field gradients. This mechanism
deposits energy efficiently in the lower corona, and we show that the spatial
distribution of the heating is determined by the mean density through the
Alfven speed profile. This provides a robust heating mechanism that can explain
observed high coronal temperatures and accounts for the significant heating
(per unit volume) distribution below two solar radius needed in models of the
origin of the solar wind. The obtained heating per unit mass on the other hand
is much more extended indicating that the heating on a per particle basis
persists throughout all the lower coronal region considered here.Comment: 19 pages, 5 figures. Accepted for publication in Ap
AMMI & GGE BIPLOT: uma análise comparativa da avaliação de locais de teste de genótipos de arroz.
Ensaios de Valor de Cultivo e Uso (VCU) são de grande importância no melhoramento de plantas. A análise desses experimentos é comumente realizada utilizando-se diversas ferramentas estatísticas. Entre estas, nos últimos anos tem ganhado aplicação crescente análises como AMMI (Additive Main effects and Multiplicative Interaction) e GGE biplot (Genotype main effects and Genotype x Environment interaction effects)
Variational calculations with improved energy functionals in gauge theories
For a SU(N) Yang-Mills theory, we present variational calculations using
gaussian wave functionals combined with an approximate projection on gauge
invariant states. The projection amounts to correcting the energy of the
gaussian states by substracting the spurious energy associated with gauge
rotations. Based on this improved energy functional, we perform variational
calculations of the interaction energy in the presence of external electric and
magnetic fields. We verify that the ultraviolet behaviour of our approximation
scheme is consistent, as it should, with that expected from perturbation
theory. In particular, we recover in this variational framework the standard
one-loop beta function, with a transparent interpretation of the screening and
anti-screening contributions.Comment: 40 pages, no figure
Variáveis climáticas e produtividade do feijoeiro no Centro-Oeste.
Devido às mudanças climáticas, há demanda para os programas de melhoramento de plantas para o desenvolvimento de cultivares consideradas adaptadas às condições climáticas em uma determinada área alvo. A caracterização ambiental é essencial para identificar os impactos ambientais relevantes que impulsionam a estabilidade da produtividade e adaptabilidade nas regiões de produção. Assim, quantificou-se os efeitos dos fatores climáticos na adaptação do germoplasma de feijoeiro nas três épocas de cultivo, das águas, da seca e de inverno, no Centro-Oeste
Classificação da incidência de área gessada do arroz de terras altas e o impacto das variáveis climáticas.
O gessamento no grão de arroz torna-o opaco, mais quebradiço e com maior probabilidade de empapamento, portanto diminui a qualidade, além do valor de mercado. É um problema altamente influenciado por adversidades meteorológicas durante a safra. Até então, não há classificação oficial definida para a área gessada. Este estudo objetivou estabelecer uma classificação para a área gessada e determinar as variáveis climáticas que mais impactam esse defeito. Dados de quatro experimentos realizados em Porangatu, GO, e Vilhena, RO, safras 2018/2019 e 2019/2020, com 11 genótipos contrastantes, foram utilizados. A análise estatística foi dividida em três passos: 1) análise dos valores preditos da área gessada de 11 genótipos; 2) classificação dos valores preditos; e 3) análise classificatória para a indicação das variáveis climáticas mais discriminantes nos níveis de incidência de área gessada. Como resultado, foram obtidas três classes de incidência de área gessada, alta (valores >20%), média (valores >15% e 15%). A variável meteorológica mais discriminante da incidência de área gessada foi a temperatura mínima do ar no ciclo da cultura. Valores de temperatura mínima do ar maiores que 23 ºC durante o ciclo da cultura favoreceram a incidência de área gessada.ODS
Don't tax me? : Determinants of individual attitudes toward progressive taxation
This contribution empirically analyses the individual determinants of tax rate preferences. For that purpose we make use of the representative German General Social Survey (ALLBUS) that offers data on the individual attitudes toward progressive, proportional, and regressive taxation. Our theoretical considerations suggest that beyond self-interest, information, fairness considerations, economic beliefs and several other individual factors drive individual preferences for tax rate structures. Our empirical results indicate that the self-interest view does not offer the sole explanation for the heterogeneity in attitudes toward progressive taxation. Rather, we show that the choice of the favoured tax rate is also driven by fairness considerations
Demonstration of passive plasma lensing of a laser wakefield accelerated electron bunch
We report on the first demonstration of passive all-optical plasma lensing using a two-stage setup. An intense femtosecond laser accelerates electrons in a laser wakefield accelerator (LWFA) to 100 MeV over millimeter length scales. By adding a second gas target behind the initial LWFA stage we introduce a robust and independently tunable plasma lens. We observe a density dependent reduction of the LWFA electron beam divergence from an initial value of 2.3 mrad, down to 1.4 mrad (rms), when the plasma lens is in operation. Such a plasma lens provides a simple and compact approach for divergence reduction well matched to the mm-scale length of the LWFA accelerator. The focusing forces are provided solely by the plasma and driven by the bunch itself only, making this a highly useful and conceptually new approach to electron beam focusing. Possible applications of this lens are not limited to laser plasma accelerators. Since no active driver is needed the passive plasma lens is also suited for high repetition rate focusing of electron bunches. Its understanding is also required for modeling the evolution of the driving particle bunch in particle driven wake field acceleration
Randomised phase II trial of gemcitabine plus vinorelbine vs gemcitabine plus cisplatin vs gemcitabine plus capecitabine in patients with pretreated metastatic breast cancer
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