[Clinical, immunohistochemical, and molecular genetic prognostic factors in adult patients with glioblastoma]. / Klinicheskie, immunogistokhimicheskie i molekulyarno-geneticheskie faktory prognoza u bol'nykh c glioblastomoi.

UNLABELLED: Glioblastoma is the most common primary malignant glial tumor of the brain in adult patients. AIM: to define the prognostic value of isocitrate dehydrogenase-1 (IDH-1) mutation and methylguanine-DNA methyltransferase (MGMT) methylation status in patients with glioblastoma (GB) and to analyze the impact of clinical data (gender, age, and tumor site), histological variants of the tumor structure, and time to development of recurrences on the course of the disease. SUBJECTS AND METHODS: The investigation enrolled 63 GB patients aged 18 to 71 years who had received combined treatment (surgery, chemo- and radiotherapy) at the N.I. Burdenko Research Institute of Neurosurgery, Ministry of Health of the Russian Federation, in the period 2008 to 2011. The investigators performed a morphological examination of all tumor tissue samples and an immunohistochemical examination using anti-IDH-1 R-132 antibody clone («Dianova¼, Germany) and defined MGMT methylation status by a polymerase chain reaction using the CpGenome DNA Modification Kit («Chemicon International¼, USA). The data were statistically processed using a package of Statistica 6.0 programs. RESULTS: Patient age, time to development of recurrent glioblastoma, mutations in the IDH-1 gene and MGMT were found to be prognostic factors for overall survival among adult patients in this category. CONCLUSION: Analysis of clinical findings and identification of molecular genetic aberrations in the tumor cells will be able to elaborate an individual approach to treating patients with glioblastoma in order to increase their survival rates and to improve quality of life.

Relaxation of surface tension in the free-surface boundary layer of simple Lennard-Jones liquids.

In this paper we use molecular dynamics to answer a classical question: how does the surface tension on a liquid/gas interface appear? After defining surface tension from the first principles and performing several consistency checks, we perform a dynamic experiment with a single simple liquid nanodroplet. At time zero, we remove all molecules of the interfacial layer, creating a fresh bare interface with the bulk arrangement of molecules. After that the system evolves towards equilibrium, and the expected surface tension is re-established. We found that the system relaxation consists of three distinct stages. First, the mechanical balance is quickly re-established. During this process the notion of surface tension is meaningless. In the second stage, the surface tension equilibrates, and the density profile broadens to a value which we call "intrinsic" interfacial width. During the third stage, the density profile continues to broaden due to capillary wave excitations, which does not however affect the surface tension. We have observed this scenario for monatomic Lennard-Jones (LJ) liquid as well as for binary LJ mixtures at different temperatures, monitoring a wide range of physical observables.

Superfast nonlinear diffusion: capillary transport in particulate porous media.

The migration of liquids in porous media, such as sand, has been commonly considered at high saturation levels with liquid pathways at pore dimensions. In this Letter, we reveal a low saturation regime observed in our experiments with droplets of extremely low volatility liquids deposited on sand. In this regime, the liquid is mostly found within the grain surface roughness and in the capillary bridges formed at the contacts between the grains. The bridges act as variable-volume reservoirs and the flow is driven by the capillary pressure arising at the wetting front according to the roughness length scales. We propose that this migration (spreading) is the result of interplay between the bridge volume adjustment to this pressure distribution and viscous losses of a creeping flow within the roughness. The net macroscopic result is a special case of nonlinear diffusion described by a superfast diffusion equation for saturation with distinctive mathematical character. We obtain solutions to a moving boundary problem defined by superfast diffusion equation that robustly convey a time power law of spreading as seen in our experiments.

Flow-induced dynamic surface tension effects at nanoscale.

The aim of this study is to investigate flow-induced dynamic surface tension effects, similar to the well-known Marangoni phenomena, but solely generated by the nanoscale topography of the substrates. The flow-induced surface tension effects are examined on the basis of a sharp interface theory. It is demonstrated how nanoscale objects placed at the boundary of the flow domain result in the generation of substantial surface forces acting on the bulk flow.

Effect of flow field and geometry on the dynamic contact angle.

A number of recent experiments suggest that, at a given wetting speed, the dynamic contact angle formed by an advancing liquid-gas interface with a solid substrate depends on the flow field and geometry near the moving contact line. In the present work, this effect is investigated in the framework of an earlier developed theory that was based on the fact that dynamic wetting is, by its very name, a process of formation of a new liquid-solid interface (newly "wetted" solid surface) and hence should be considered not as a singular problem but as a particular case from a general class of flows with forming or/and disappearing interfaces. The results demonstrate that, in the flow configuration of curtain coating, where a liquid sheet ("curtain") impinges onto a moving solid substrate, the actual dynamic contact angle indeed depends not only on the wetting speed and material constants of the contacting media, as in the so-called slip models, but also on the inlet velocity of the curtain, its height, and the angle between the falling curtain and the solid surface. In other words, for the same wetting speed the dynamic contact angle can be varied by manipulating the flow field and geometry near the moving contact line. The obtained results have important experimental implications: given that the dynamic contact angle is determined by the values of the surface tensions at the contact line and hence depends on the distributions of the surface parameters along the interfaces, which can be influenced by the flow field, one can use the overall flow conditions and the contact angle as a macroscopic multiparametric signal-response pair that probes the dynamics of the liquid-solid interface. This approach would allow one to investigate experimentally such properties of the interface as, for example, its equation of state and the rheological properties involved in the interface's response to an external torque, and would help to measure its parameters, such as the coefficient of sliding friction, the surface-tension relaxation time, and so on.