Detection of melanoma by monitoring the intracellular fluorescein fluorescence polarization changes in lymphocytes

The effectiveness of detecting melanoma by measuring the intracellular fluorescein fluorescent polarization (IFFP) of patients' SCM (structuredness of the cytoplasmic matrix)-responding lymphocytes was examined. SCM-responding lymphocytes from 46 melanoma patients and 32 healthy volunteers were labeled with fluorescein diacetate and challenged with different stimuli, and the resulting polarization was determined. The polarizations (P) obtained upon stimulation with nothing (P-0), encephalitogenic factor (P-EF), phytohaemagglutinin (P-PHA), or melanoma antigen (P-MEL), and the ratios RR(ef) (P-EF/P-PHA) and RR(mel) (P-MEL/P-PHA) were lower for SCM-responding lymphocytes from the patients as a group than for those of the controls. The specificity and sensitivity of the IFFP tests (using cutoff values) to detect melanoma were 90.6 and 73.9%, respectively. The IFFP tests may facilitate the discrimination between melanoma patients and healthy subjects, and may be used in follow-up of patients with melanoma.     

Automated Meta-Control for Adaptable Real-Time Software

The software meta-controller is an online agent responsible for dynamically adapting an application's software configuration, e.g. altering operational modes and migrating tasks, to best accommodate varying runtime circumstances. In distributed real-time applications such adaptations must be carried out in a manner which maintains the schedulability of all critical tasks while maximizing some notion of system value for all other tasks. For large-scale real-time applications, considering all possible adaptations at the task-level is computationally intractable. This paper presents an automated aggregate approach to software meta-control, appropriate for large-scale distributed real-time systems. The aggregate automated meta-control problem is still NP-hard, but it has very practical approximate solutions. Introduced, here, are two very-effective approximation algorithms, QDP and GG, with very reasonable polynomial time complexity. Both algorithms also provide us with upper bounds for optimum system values, useful for deriving absolute, albeit somewhat pessimistic, measures of actual performance. Extensive Monte Carlo analysis is used to illustrate that expected performance for both algorithms is generally suboptimal by no more than a few percent. Our flexible software meta-control model is also shown to be readily applied to a wide range of time-sensitive applications.     

Dependence of crack trajectories on stress distributions in the surfaces of injection moldings produced under high packing pressure

The curved trajectories of solvent-induced cracks in the surfaces of polycarbonate injection moldings produced under high packing pressures have been rationalized in terms of the residual body stresses that exist largely in a thin surface layer. The analysis indicates that the residual tensile stress in the skin of the molded plaque can reach values as large as 5 MPa and the tangential tensile stress values as large as 12 MPa, depending on location in the plaque and on molding conditions. The inward penetration of the crack is stopped eventually by the interior compressive stresses that counterbalance the tensile stresses in the “skin.” The crack tends to turn sideways and grow further in Mode II as a result of the intense interlayer shear stress set up at the crack tip by the difference between the skin tension and core compression. The most important practical conclusion from this analysis is that in the absence of externally applied stress, these so-called edge cracks are unlikely to penetrate the molding's interior since the tensile stress in the surface layer is necessarily counterbalanced by the subsurface compression.     

Hydration of polyethylene glycol-grafted liposomes

In this report we describe the identification, cloning, and expression pattern of human cytokine-like factor 1 (hCLF-1) and the identification and cloning of its murine homologue. They were identified from expressed sequence tags using amino acid sequences from conserved regions of the cytokine type I receptor family. Human CLF-1 and murine CLF-1 shared 96% amino acid identity and significant homology with many cytokine type I receptors. CLF-1 is a secreted protein, suggesting that it is either a soluble subunit within a cytokine receptor complex, like the soluble form of the IL-6R alpha-chain, or a subunit of a multimeric cytokine, e.g., IL-12 p40. The highest levels of hCLF-1 mRNA were observed in lymph node, spleen, thymus, appendix, placenta, stomach, bone marrow, and fetal lung, with constitutive expression of CLF-1 mRNA detected in a human kidney fibroblastic cell line. In fibroblast primary cell cultures, CLF-1 mRNA was up-regulated by TNF-alpha, IL-6, and IFN-gamma. Western blot analysis of recombinant forms of hCLF-1 showed that the protein has the tendency to form covalently linked di- and tetramers. These results suggest that CLF-1 is a novel soluble cytokine receptor subunit or part of a novel cytokine complex, possibly playing a regulatory role in the immune system and during fetal development.     

Fracture conditions of a crack approaching a disturbance

The conditions which drive a crack to propagate in the vicinity of a cylindrical disturbance (cavity, bonded or unbonded inclusion) is expressed by linear fracture mechanics terms. A basic elastic solution with three levels of converging approximations is proposed and compared with finite element solution. The major finding is that a cavity under a given transverse (to cylindrical axis) tensile load attracts a nearby crack and promotes local fracture, whereas a rigid perfectly bonded inclusion repels the crack advancement and arrests local fracture. Unbonded or weakly bonded inclusion fall between those limits. Quantitative values of the relative stress intensity factor are given for large spectrum of geometries and elastic constants. A complementary numerical study is focused on the effect of a thin-layered binder around the inclusion on the stress intensity factor at the crack tip while approaching the binder. The conclusion is that the binder should be as thin as possible and with high shear modulus in order not to neutralize the local toughening effect of the inclusion.

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Résumé Les conditions qui gouvernent la propagation d'une fissure au voisinage d'une discontinuité cylindrique (cavité, inclusion soudée ou non) peuvent être décrites par la théorie linéaire de la mécanique de rupture. On propose, et on compare à une solution par éléments finis, une solution élastique de base comportant trois niveaux d'approximations convergentes. On trouve essentiellement qu'une cavité sujette à une charge de traction transversalement à son axe cylindrique a pour effet d'attirer une fissure en son voisinage et provoquer une rupture locale. Par contre, une inclusion rigide et parfaitement soudée repousse l'avance de la fissure et provoque un arrêt de la rupture.Des inclusions non soudées ou partiellement soudées ont un effet situé entre ces deux limites. On fournit des valeurs quantitatives du facteur d'intensité des contraintes, pour un large spectre de géométries et de constantes élastiques. Une analyse numérique complémentaire est centrée sur l'effet d'un film de liaison autour de l'inclusion sur le facteur d'intensité des contraintes à l'extrémité de la fissure lorsque celle-ci avoisine cette zône de liaison.On en conclut que le film de liaison devrait être aussi mince que possible et posséder un module de cisaillement élevé, afin de neutraliser l'effet de durcissement local de l'inclusion.

     

Incipient fracture angle,fracture loci and critical stress for mixed mode loading

A prediction of the direction of incipient crack growth in brittle-like materials and the associated fracture loci under mixed mode loading is proposed. It is postulated that the direction of unstable crack propagation is determined by the “weakest” near-tip element defined as the one which would relax maximum potential energy upon prospective crack extension. Starting from the energy rate principle of crack extension (Eshelby energy-momentum tensor and Rice $\text{J-}\text{internal}$ vector) it is deduced that a crack will extent in the direction along which the following stress criterion is satisfied, $\text{(δ}{}_{\mathrm{\theta \theta }}{}^2\text{? δ}{}_{\mathrm{rr}}{}^2\text{) →}\text{maximum (for}\text{δ}{}_{\mathrm{\theta \theta \; >\; 0)}}$ The fracture angle in pure Mode II (70.4° away from the original straight path) is shown to be unstable in the sense that any slight tension along the crack (non-singular at the crack tip) affects considerably (up to 22%) the directionality of crack extension. It appears to be sensitive to the extent of the near-tip zone ($\text{r}{}_0$) in which linear elasticity does not hold and the non-singular stress term (squared).The fracture loci in mixed mode loading (generated by projecting the $\text{J-}\text{integral}$ vector along the prospective fracture path and letting this scalar function attain a critical value) is quadratic in $\text{K}{}_1$ and $\text{K}{}_2$ with an interactive cross product term $\text{K}{}_1\text{× K}{}_2$.The suggested criterion with its implication in predicting critical fracture load, exhibits behavior which is consistent with experimental observations collected from several sources. The common and uncommon features with respect to other known criteria are compared and discussed.     

Assessments of the kinetic and dynamic loads sustained by stationary tools during high rate plastic forming

A systematic method for evaluating the kinetic and dynamic loads sustained by stationary tools (as opposed to moving tools for which methods already exist) during high rate plastic forming is examined and exemplified by examples. It is essentially based on the momentum theorem for continua for incompressible flow, utilizing kinematically admissible velocity fields. In steady state forming processes (such as rolling, wire drawing, etc.), the difference between the active load (imposed or calculated a priori) and the reactive load, is formulated rigorously, whereas for non-steady processes (forging, impact extrusion, etc.) the formulation gives merely an approximation to the dynamic effects on the tools. The resulting velocity-dependent reactions on the tools are given in terms of two nondimensional numbers, namely, the “kinetic head” (u₀²/σ₀) (called the Euler Number) and the “dynamic head” (ú₀L/σ₀), which includes the machine speed (u₀), machine acceleration ( ), material density , yield strength ₀ and a characteristic dimension of the product, L. The same two non-dimensional heads emerged previously from energy-balance consideration in Ref. [1], while approximating dynamic loads on moving tools, hence a consistency is demonstrated. These heads are unavoidably multiplied by geometrical functions, which typify the specific process under consideration and may amplify (or diminish) the intensity of the dynamic effects. The present work is focussed on quantifying, by the above method, the inherent difference between the reactive load sustained by the non-moving tool (say, a die) and the acting load carried by the moving tool (piston, ram, etc.) In particular cases of very slow processes, these loads are equal by static equilibrium. In some practical processes (like rolling) their difference appears to be relatively small, whereas in others (like impact extrusion) it appears extremely large.     

The role of die curvature in the performance of deep drawing (hydro-mechanical) processes

A hydromechanical deep drawing process (which replaces the conventional rigid blank-holder tool with a hydrostatic fluid pressure) is utilized to study the roles played by die curvature, interfacial friction, material hardening, etc. in deep drawing performance. The analytical study is based on limit analysis in plasticity (applying both the upper and the lower bounds simultaneously) with a special emphasis on the geometry of the die profile. The resulting relationships between the various parameters obtained through the bounds are backed by an independent numerical solution using Woo's finite difference scheme. The associated experiments, with which the limit analysis is compared, were conducted with aluminium blanks at various die radii and with various holding fluid pressures.The relatively close proximity of the above solutions, in describing the observed behaviour of the process, enables one to draw a few general conclusions about the strength of the limit analysis in describing realistic deep drawing processes. Also potential improvements concerning the choice of die radius of curvature and the blank holding force are indicated.