New application of carbon nanotubes in haemostatic dressing filled with anticancer substance.

The drug-carrier system used as innovative haemostatic dressing with oncostatic action is studied. It is obtained from CDDP (cisplatin) doped SWCNT (single walled carbon nanotubes), modified and purified by H2O2 in hydrothermal treatment process. In the in vivo nephron sparing surgery (NSS) study we used 35 BALB/c nude mice with induced renal cancer using adenocarcinoma 786-o cells. Animals were divided into four groups: CDDP(M-), CDDP(M+), CONTROL(M-) and CONTROL(M+). In CDDP(M-) and CDDP(M+) groups we used, intraoperatively, carbon nanotubes filled with cisplatin (CDDP). In CONTROL(M-) and CONTROL(M+) groups carbon nanotubes were used alone. During NSS free margin (M-) or positive margin (M+) was performed. In the CDDP(M-) group, we do not observe local tumor recurrences. In Group CDDP(M+) only one animal was diagnosed with tumor recurrence. In control groups the recurrent tumor formation was observed. In our study, it is shown that CDDP filled SWCNT inhibit cancer recurrence in animal model NSS study, and can be successfully applied as haemostatic dressings for local chemoprevention.

Equilibrium clusters in concentrated lysozyme protein solutions.

We have studied the structure of salt-free lysozyme at 293 K and pH 7.8 using molecular simulations and experimental SAXS effective potentials between proteins at three volume fractions, ϕ=0.012, 0.033, and 0.12. We found that the structure of lysozyme near physiological conditions strongly depends on the volume fraction of proteins. The studied lysozyme solutions are dominated by monomers only for ϕ≤0.012; for the strong dilution 70% of proteins are in a form of monomers. For ϕ=0.033 only 20% of proteins do not belong to a cluster. The clusters are mainly elongated. For ϕ=0.12 almost no individual particles exits, and branched, irregular clusters of large extent appear. Our simulation study provides new insight into the formation of equilibrium clusters in charged protein solutions near physiological conditions.

Determination of the space between closed multiwalled carbon nanotubes by GCMC simulation of nitrogen adsorption.

We present a new determination method of the porosity created by the adsorption space between closed multiwalled carbon nanotubes. Using the grand canonical Monte Carlo (GCMC) simulation of nitrogen adsorption at 77 K and applying the "Karolina" algorithm, local isotherms were simulated for different distances between parallel nanotubes and finally the equation of the global adsorption isotherm was solved. This methodology leads to a satisfactory description of the experimental nitrogen adsorption data showing that the distance between nanotubes is in the range between 4 and 14 nm.

Numerical analysis of Horvath-Kawazoe equation.

A new Determining Horvath-Kawazoe (DHK) program for the evaluation of pore-size distribution curve based on the HK method (J. Chem. Eng. Jpn. 16 (1983) 470) is described. The standard bisection procedure (Gerald, C.F., 1977. Applied Numerical Analysis, 2nd ed. Addison-Wesley, CA) is used as a kernel in the proposed algorithm. The calculation of the effective pore-size distribution and the comparative analysis with the previous data published by Horvath and co-workers (J. Chem. Eng. Jpn. 16 (1983) 470; Fraissard, J., Conner, C.W., 1997. Physical Adsorption: Experiment, Theory and Applications. Kluwer Academic, London) and recalculated by Do (Do, D.D., 1998. Adsorption Analysis: Equilibria and Kinetics. Imperial College Press, London) were done.

The Characterization of Microporous Activated Carbons Utilizing a Simple Adsorption Genetic Algorithm (SAGA).

The paper presents a new simple adsorption genetic algorithm (SAGA) which is based on the genetic theory of natural selection and rivalry. This algorithm is utilized to estimate the parameters of the Dubinin-Rhadushkevich equation. The obtained results are compared with these achieved from the classical optimization methods. The analysis of the error of fitting of the DR model to experimental data is discussed. It is shown that the proposed SAGA, contrary to the other methods, makes it possible to calculate the parameters of the DR equation not only very precisely but also very quickly. Copyright 2001 Academic Press.