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101.
VA Belitser TV Varetskaia SN Tsynkalovskaia LA Tsariuk LI Shevchenko 《Canadian Metallurgical Quarterly》1976,48(4):521-532
A new diagnostic method to determine fibrinogen and fibrin splitting products is based on the fact that high-molecular fragments acting as specific inhibitors of fibrin self-assembly compose these products. Fibrinogen and fibrin splitting products are detected and determined quantitatively by prolongation of coagulation time in the test with the standard monomeric fibrin. The number of units of anticoagulating activity in the studied urine are the results of the determinations. Sensitivity of the method if necessary may be increased by adding of a certain amount of the fibrinogen and fibrin splitting products to the test that makes a favourable background for the action of the products. The method is rather sensitive, reliable and simple. It may be used in ordinary clinical laboratories. The method proved to be quite satisfactory when testing renal diseases at the clinic. It is of great significance for early detection of the transplanted kidney rejection. The new method is compared with the known immunological method which consist in determination of the inhibitory effect of the fibrinogen and fibrin splitting products on agglutination of erythrocytes of specific antibodies; the erythrocytes being subjected to "tanning" and "loading" with fibrinogen. A satisfactory correlation is found between the results of two methods. 相似文献
102.
R. Černý J. Poděbradská M. Totová J. Toman J. Drchalová P. Rovnaníková P. Bayer 《Materials and Structures》2004,37(9):597-607
The effect of elevated temperatures on basic hygric and thermal properties of three types of glass fiber reinforced cement
composites (GFRC) is analyzed in the paper. The main difference in the composition of particular GFRC is the use of wollastonite
and vermiculite in two of them instead of usual sand aggregates. The composites containing wollastonite and vermiculite are
found to have about four times lower thermal conductivity and two to three times lower thermal diffusivity in room temperature
conditions. After heating the samples to 800°C and subsequent cooling, a decrease in room-temperature thermal conductivity
as high as 50% and an increase in moisture diffusivity in the range of one to two orders of magnitude are observed for all
types of studied materials. The application of wollastonite and vermiculite exhibits a positive effect on the high temperature
linear thermal expansion coefficient. On the other hand, for temperatures higher than 450°C the thermal diffusivity of materials
with wollastonite and vermiculite is higher than of common GFRC with sand aggregates.
Résumé L'effet des températures élevées sur les principales propriétés hygriques et thermiques de trois types de matériaux composites à base de ciment renforcés par des fibres de verre (GFRC) est analysé dans cet article. La différence majeure de composition de ces matériaux est l'utilisation de wollastonite et de vermiculite dans deux d'entre eux au lieu des granulats de sable habituels. Les matériaux composites contenant de la wollastonite et de la vermiculie s'avèrent posséder une conductivité thermique environ quatre fois inférieure et une diffusivité thermique deux à trois fois inférieure en conditions de température ambiante. Après avoir chauffé les échantillons à 800°C puis les avoir refroidis, on observe pour tous les types de matériaux étudiés une diminution de la conductivité thermique à température ambiante, à hauteur de 50%, et une augmentation de la diffusivité d'humidité, d'environ un à deux ordres de grandeur. L'application de la wollastonite et de la vermiculite montre un effet positif sur le coefficient linéaire à haute température de dilatation thermique. D'autre part, pour les températures supérieures à 450°C, la diffusivité thermique des matériaux contenant de la wollastonite et de la vermiculite est plus élevée que celle des GFRC communs avec des granulats de sable.相似文献
103.
Stability analysis is of great significance in those feedback control systems in which the power amplifier is operated as a pulse-modulator device, since under these circumstances the whole control system is highly non-linear. Stability in PWM feedback control systems with a proportional type regulator has been amply described in the literature. Only recently, however, have such studies been extended to include systems with a proportional-plus-integral regulator. In this paper the problem is considered for the case involving a PWM control system, where the regulator is a proportional-plus-integral-plus-derivative, the PWM modulator is of a very general type and the controlled process is of arbitrary order. The stability of the system is analysed by means of a discrete version of the second Lyapunov method ; this method in turn leads to an investigation of the positivity region of a quadratic form defined in the parameter space of the regulator. To improve the stability region obtained, a procedure is investigated whereby only a few parameters of the quadratic Lyapunov function need to be varied. The method proposed has proved extremely simple and flexible to apply, even in cases where the system is of arbitrary order. 相似文献
104.
M. DE LA SEN 《控制论与系统》2013,44(2-3):125-150
Abstract A perturbation theory for evaluation algorithms of arithmetic expressions is applied to the generalized least-squares identification of the continuous parameters by using nonperiodic discrete data. The sampling instants are distributed in such a way that a sequence of the elemental arithmetic expressions of the identification algorithm are suboptimized according to bang-bang rules on the extrema of appropriate variation intervals. The weighting scalars in the generalized least-squares method are updated with the same purpose. 相似文献
105.
Tomas Bayer 《GeoInformatica》2014,18(3):621-669
This article presents a new off-line method for the detection, analysis and estimation of an unknown cartographic projection and its parameters from a map. Several invariants are used to construct the objective function ? that describes the relationship between the 0D, 1D, and 2D entities on the analyzed and reference maps. It is minimized using the Nelder-Mead downhill simplex algorithm. A simplified and computationally cheaper version of the objective function ? involving only 0D elements is also presented. The following parameters are estimated: a map projection type, a map projection aspect given by the meta pole K coordinates [φ k , λ k ], a true parallel latitude φ 0, central meridian longitude λ 0, a map scale, and a map rotation. Before the analysis, incorrectly drawn elements on the map can be detected and removed using the IRLS. Also introduced is a new method for computing the L 2 distance between the turning functions Θ1, Θ2 of the corresponding faces using dynamic programming. Our approach may be used to improve early map georeferencing; it can also be utilized in studies of national cartographic heritage or land use applications. The results are presented both for the real cartographic data, representing early maps from the David Rumsay Map Collection, and for the synthetic tests. 相似文献
106.
107.
Progress towards a methodology for high throughput 3D reconstruction of soot nanoparticles via electron tomography
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The aim of this work is to make progress towards the development of 3D reconstruction as a legitimate alternative to traditional 2D characterization of soot. Time constraints are the greatest opposition to its implementation, as currently reconstruction of a single soot particle takes around 5–6 h to complete. As such, the accuracy and detail gains are currently insufficient to challenge 2D characterization of a representative sample (e.g. 200 particles). This work is a consideration of the optimization of the steps included within the computational reconstruction and manual segmentation of soot particles. Our optimal process reduced the time required by over 70% in comparison to a typical procedure, whilst producing models with no appreciable decrease in quality. 相似文献
108.
Michael Singh Serhat Akkaya Mark Preuß Franziska Rademacher Mersedeh Tohidnezhad Yusuke Kubo Peter Behrendt Jan-Tobias Weitkamp Thilo Wedel Ralph Lucius Regine Glser Jürgen Harder Andreas Bayer 《International journal of molecular sciences》2022,23(5)
Platelet-released growth factors (PRGFs) or other thrombocyte concentrate products, e.g., Platelet-Rich Fibrin (PRF), have become efficient tools of regenerative medicine in many medical disciplines. In the context of wound healing, it has been demonstrated that treatment of chronic or complicated wounds with PRGF or PRF improves wound healing in the majority of treated patients. Nevertheless, the underlying cellular and molecular mechanism are still poorly understood. Therefore, we aimed to analyze if PRGF-treatment of human keratinocytes caused the induction of genes encoding paracrine factors associated with successful wound healing. The investigated genes were Semaphorin 7A (SEMA7A), Angiopoietin-like 4 (ANGPLT4), Fibroblast Growth Factor-2 (FGF-2), Interleukin-32 (IL-32), the CC-chemokine-ligand 20 (CCL20), the matrix-metalloproteinase-2 (MMP-2), the chemokine C-X-C motif chemokine ligand 10 (CXCL10) and the subunit B of the Platelet-Derived Growth Factor (PDGFB). We observed a significant gene induction of SEMA7A, ANGPLT4, FGF-2, IL-32, MMP-2 and PDGFB in human keratinocytes after PRGF treatment. The CCL20- and CXCL10 gene expressions were significantly inhibited by PRGF therapy. Signal transduction analyses revealed that the PRGF-mediated gene induction of SEMA7A, ANGPLT4, IL-32 and MMP-2 in human keratinocytes was transduced via the IL-6 receptor pathway. In contrast, EGF receptor signaling was not involved in the PRGF-mediated gene expression of analyzed genes in human keratinocytes. Additionally, treatment of ex vivo skin explants with PRGF confirmed a significant gene induction of SEMA7A, ANGPLT4, MMP-2 and PDGFB. Taken together, these results describe a new mechanism that could be responsible for the beneficial wound healing properties of PRGF or related thrombocytes concentrate products such as PRF. 相似文献
109.
110.
M. DE LA SEN 《International journal of control》2013,86(6):1769-1775
In this note, it is proved that stability of composite systems including parallel subsystems can be achieved for certain sets of initial conditions and additional stability assumptions for the non-hyperstable subsystems. It is required that at least one subsystem be asymptotically hyperstable. 相似文献