DL-Poly

Setlow et al.83 have studied the photolysis of poly dl poly dC (polydeoxyinosinic acid polydeoxycytidylic acid, see Glossary) and poly dA dT. The photochemical changes were estimated by following absorbance changes, by chromatographic separation of acid hydrolysates, and by chromatographic separation of products from enzymatic hydrolysates. 

Viscometry The specific viscosity of each polymer from the bulk polymerization was measured in acetone at 30°C using an Ubbelohde dilution viscometer. Five concentrations in the range of 1.120 to 0.242 g/d poly(vinyl acetate) and polyvinyl trideuteroacetate) and 0.385 to 0.084 g/dl (poly(trideu-terovinyl acetate)) were run. Intrinsic viscosity was calculated by extrapolation of the Tlsp/c versus c plot to zero concentration. Number average molecular weights were calculated using the equation(20) [q] =1,0 x 10 1 [Mn] 0 72 which is in the mid range of the equations listed. 

Todorov, I.T., and W. Smith. 2004. DL POLY 3 The CCP5 national UK code formolecular-dynamics simulations. One contribution of 12 to a theme Discrete element modelling Methods and applications in the environmental sciences. Phil. Trans. R. Soc. Lond. A 362 1835-1852. 

Finally, we draw attention to a parallel macromolecular simulation package, DL POLY, currently under development, which incorporates many of the parallel developments of Smith and co-workers. 

Zoladex is DL-poly-lactide-glycolide. The implants are cylindrical in shape and have a diameter enabling the application by syringes and injection needles. A scheme of the preparation of this type of implants is... 

There have been some molecular dynamics simulations with anisotropic atom-atom potentials, the earliest being simulations with chlorine poten-tials. " Those simulations demonstrated that the computer time requirements were quite reasonable, and the results were effective compared with the inclusion of additional isotropic sites. The technique has also been extended to butane by means of a four-site anisotropic carbon model. A general DMA based potential model is being implemented into the new CCP5 molecular simulation program DL POLY. Monte Carlo simulations can use anisotropic atom-atom potentials readily, " since the calculations require the evaluation of only the energy. 

W. Smith and T. R. Forester, J. Mol. Graphics, 14, 136 (1996). DL Poly 2.0—A General Purpose Parallel Molecular Dynamics Simulation Package. 

Note DL-PLG Dl-poly(lacfic-co-glycolic acid) DL-PIA DL-polylactic acid L-PLA L-polylactic acid PGA polyglycolic acid PCL poly-e-caprolacfone. 

Kitchell JP, Wise DL. Poly(lactic/glycolic acid) biodegradable drug-polymer matrix systems. Methods Enzymol 1985 112 436-448. 

The present version of SDIBEX is designed to use both QM and QCT calculations. However, only one QCT conij)utational engine (ABCtraj [26] for three atom systems) is fully operative while other two ( enus[27] for more than three atom systems and DL POLY [28] for many atom systems) are still in the process of being implemented. 

The long-range Coulomb interactions were treated using the 3D Ewald summation method with Ewald convergence parameter a = 0.284 A-1 and an Ewald sum precision of 1 10-5 (from the standard in the DL POLY package [35]). 

DL POLY. DL POLY is a parallel molecular dynamics simulation package originally developed at the Daresbury Laboratory in England. Parameters for the current DL POLY 3 force field may be obtained from the GRO-MOS, AMBER, and DREIDING force fields that share functional forms. 

Proikakis CS, Mamouzelos NJ, Tarantili PA et al (2003) Stability of DL-poly(lactic acid) in aqueous solutions. J Appl Polym Sci 87 795-804... 

Smith W, Yong CW, Rodger PM (2002) DL-POLY application to molecular simulation. Mol Simul 28 385 71... 

The potential parameters for the water molecule were empirically fitted to reproduce the experimental dipole moment, 0-H bond length and H-O-H angle of the water monomer and the structure of the water dimer and infra-red data. Molecular dynamics simulations were then used to calculate the self-diffusion coefficient, radial distribution functions (RDFs) and energy of evaporation of liquid water. The computer code DL POLY 2.6 code (Forester and Smith 1995) was employed. We simulated a box containing 256 water molecules at a temperature of 300 K where the conditions were initially set at the experimental density of p= 1.0 g/cm and run with an NPT ensemble. We chose a mass for the oxygen shell of 0.2 a.u., which is small compared to the mass of the hydrogen atom of 1.0 a.u. However, due to the small shell mass we needed to run the MD simulation with the small timestep of 0.2 fs in order to keep the system stable. With this timestep we obtained data at constant pressure and temperature for a period of 100 picoseconds. 

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