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Melt electrospinning is one aspect of electrospinning with relatively little published literature, although the technique avoids solvent accumulation and/or toxicity which is favoured in certain applications. In the study reported, we melt-electrospun blends of poly(ε-caprolactone) (PCL) and an amphiphilic diblock copolymer consisting of poly(ethylene glycol) and PCL segments (PEG-block-PCL). A custom-made electrospinning apparatus was built and various combinations of instrument parameters such as voltage and polymer feeding rate were investigated. Pure PEG-block-PCL copolymer melt electrospinning did not result in consistent and uniform fibres due to the low molecular weight, while blends of PCL and PEG-block-PCL, for some parameter combinations and certain weight ratios of the two components, were able to produce continuous fibres significantly thinner (average diameter of ca 2 µm) compared to pure PCL. The PCL fibres obtained had average diameters ranging from 6 to 33 µm and meshes were uniform for the lowest voltage employed while mesh uniformity decreased when the voltage was increased. This approach shows that PCL and blends of PEG-block-PCL and PCL can be readily processed by melt electrospinning to obtain fibrous meshes with varied average diameters and morphologies that are of interest for tissue engineering purposes. Copyright © 2010 Society of Chemical Industry

This paper is about the development of a forecasting model that has been used in the Mexican Institute for Adult Education. This institute is in charge of an adult education program that is based on 42 modules, each of which requires books and materials each year. Accurate forecasts are needed to reduce the costs of wastage and shortages. Using data from previous years, the structure of the program, and interviews with officials in the Institute, we have developed a forecasting model based on Bayesian estimation. We further developed an approach that combines simulation with forecasting techniques, which may be appropriate when using a complex forecasting model. The initial results are encouraging, and we believe that the approach can be used in other situations, especially those concerned with service encounters. Our model also helps officials to understand several aspects of the education program.

The Hausdorff dimension and measure of the set of simultaneously ψ-approximable points lying on integer polynomial curves is obtained for sufficiently small error functions. §

Two block copolymers consisting of biodegradable segments of poly(ethylene glycol) (PEG) and poly(e-caprolactone) (PCL) with slight different lengths of soft hydrophilic segments (PEG) and molecular weight were produced. The copolymer with shorter PEG segments and higher molecular weight was named copolymer A, while the other copolymer B. Both copolymers were dissolved in dichloromethane at the same concentration (5% w/v) and electrospun. Different combinations of spinning voltage (SV) and distance needle to collector were used. Electrospun A copolymer showed curly and uniform fibers with an average diameter of 2 μm, while B copolymer fibers were straight, uneven, and much thinner (submicrometric). In the latter case, fiber bundles and beads were also present. Viscosity measurements on the solutions before spinning showed a viscosity of 13.0 mPa s for A copolymer solution and 5.5 mPa s for B copolymer. The mechanical properties on dog-bone shaped samples from the electrospun material evidenced that A copolymer had much higher stress and elongation at break but approximately the same elastic modulus as compared to B copolymer. Fiber morphology and mechanical properties of electrospun block copolymers are deeply influenced by different amount and length of soft and hard segments, and block copolymers can be the best suited systems to fit several applications because of the broad range of properties they show upon changing the composition ratio and molecular weight of components. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The neurotropic herpes simplex virus mutant HSV1716 lacks the gene encoding the virulence factor ICP34.5 and cannot replicate in non-dividing cells where proliferating cell nuclear antigen (PCNA) is not actively engaged in cellular DNA synthesis. In the brain, tumoral expression of PCNA therefore confers on it oncolytic specificity and may determine its efficacy. Three phase I trials in glioma patients and one in metastatic melanoma patients have established that HSV1716 is safe and replicates selectively in tumour tissue. Here we examine the in situ PCNA profiles of common human metastatic brain tumours and determine their in vitro permissivity for HSV1716 replication to ascertain their suitability for HSV1716 therapy.Histological sections of tumour biopsies obtained from patients undergoing craniotomies were stained for PCNA expression. The replicative ability of HSV wild-type (17(+)) and mutant (1716) viruses was assessed in tissue cultures of the same tumour biopsies and in cancer cell lines by plaque assay.Biopsies of all 10 metastatic tumours (3 melanoma, 4 carcinoma and 3 adenocarcinoma) as well as 4 glioblastoma multiforme were positive for PCNA immunoexpression and supported the replication of HSV1716. The PCNA-positive cells in the metastatic tumours were distributed comparatively in larger and more contiguous areas than in glioblastoma (1.69 +/- 1.61 mm(2) vs. 0.73 +/- 0.77 mm(2)) and numbered 29.0 +/- 12.4 and 12.6 +/- 4.7%, respectively.The results show that human cerebral metastatic tumours have generally larger and more contiguous proliferative areas, support efficient HSV1716 replication, and are thus potential candidates for such oncolytic viral therapy.