Carbon Nanotube Substrates for Tissue Engineering Applications : Analysis of surface nanotopography, cellular adhesion, and elasticity

The present study investigates the applicability of multiwalled carbon nanotubes in creating novel nanostructured matrices exhibiting biomimetic designed features. The thus produced CNT-based constructs were employed to gain a deeper insight into the cellular response to nanoscale structures, especially to effects resulting from the local topography. The first part of the work comprises the mechanical characterization of the CNTs matrices by means of nanoindentation and nanoscratch experiments, revealing a good mechanical stability of the MWNT-based polymer matrices. The biocompatibility of the MWNTs constructs and cell-matrix surface interaction was assessed using human osteoblast-like cells. In general, osteoblasts were found to adhere and proliferate on all nanostructured matrices. The observed increase of osteoblastic metabolic activity after incubation on CNTs matrices proved their capability to support long-term survival of osteoblast cells and excluded the toxic impact of carbon nanotubes on cell viability. Furthermore, results from immunofluorescence staining revealed the improved cell adhesion capacity to nanostructured matrices and clearly showed the sensitivity of the cell to physical features at the nanoscale. The atomic force microscopy was applied to investigate the cytomechanical properties of osteoblast cells cultured on diverse CNT matrix topographies. Experimental data showed that cell adhesion and therefore the elastic modulus of the cells are affected by the regularity of the topography, i.e., regular topography contributed to increased Young’s modulus, whereas irregular one led to decreased cell stiffness. Concluding, it could be shown that carbon nanotubes can be effectively used to fabricate various nanoscale topographies, which in turn have a powerful influence on osteoblasts behavior. The results furthermore indicate that carbon nanotubes can mimic nanofeatures of the native extracellular matrix and may therefore find an application in the design of new biomaterials for tissue engineering

Personality predictors of creative achievement and lawbreaking behavior

This article investigates how Big Five personality traits are related to creative achievements and lawbreaking behavior in a large sample (N = 1669) of Polish adults. Structural equation modelling with personality modelled as a bi-factor structure demonstrated a weak, yet significant link (r = .21) between latent factors of creative achievements and lawbreaking behavior. A general factor of personality was unrelated to creative achievement, but negatively linked to lawbreaking behavior. Lawbreaking behavior was also negatively predicted by conscientiousness and agreeableness, while only openness positively predicted creative achievement. A person-centered analysis illustrated three distinct personality profiles: resilient, undercontrolled, and overcontrolled that differed in both lawbreaking behavior and creative achievements

Key parameters in thermally conductive polymer composites

The thermal conductivity of polymer composites is measured for several tubular carbon nanofillers (nanotubes, fibres, and whiskers). The highest enhancement in the thermal conductivity is observed for functionalized multiwalled carbon nanotubes (90% enhancement for 1 vol. %) and Pyrograf carbon fibres (80%). We model the experimental data using an effective thermal medium theory and determine the thermal interface resistance (RK ) at the filler-matrix interface. Our results show that the geometry of the nanofibres and the interface resistance are two key factors in engineering heat transport in a composite

Spain’s Economic Growth between 1946—1964 with Special Attention Focussed on Stabilization Programme of the Economy from 1959

The article analyzes the crucial event in the economic policy of Spain which was launching of the stabilization programme in 1959. In the period of 1945—1950 the Spanish economy had a ąuasi autarkic character. There were being developed almost all industries with no consideration given to profitability of the domestic production. This led to increase of production costs and caused a situation in which Spanish products due to thier poor quality were hardly competitive in the world market as compared with foreign products. The launching of the stabiliza tion programme brought about an acceleration of the economic growth rate. Over the period of 1960— 1968 the economic growth rate amounted to 7.77 per cent on the annual average. That constituted a beginning of Spain’s economic boom reflecting such phenomena as rapid exp an sion of foreign tourism in Spain and increasing transfers from Spanish workers employed outside the country. As a result of industrialization the structure of Spain's economy underwent changes. The industrialization process produced a decrease in the number of people employed in agriculture and an increase in the number of those employed in industry and service sector of the economy.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę

Personality predictors of creative achievement and lawbreaking behavior

This article investigates how Big Five personality traits are related to creative achievements and lawbreaking behavior in a large sample (N = 1669) of Polish adults. Structural equation modelling with personality modelled as a bi-factor structure demonstrated a weak, yet significant link (r =.21) between latent factors of creative achievements and lawbreaking behavior. A general factor of personality was unrelated to creative achievement, but negatively linked to lawbreaking behavior. Lawbreaking behavior was also negatively predicted by conscientiousness and agreeableness, while only openness positively predicted creative achievement. A person-centered analysis illustrated three distinct personality profiles: resilient, undercontrolled, and overcontrolled that differed in both lawbreaking behavior and creative achievements.This study was possible thanks to the funding obtained from National Science Centre, Poland (UMO2012/07/B/HS6/ 01438) for the last author

The Origin of High Thermal Conductivity and Ultralow Thermal Expansion in Copper–Graphite Composites

We developed a nanocomposite with highly aligned graphite platelets in a copper matrix. Spark plasma sintering ensured an excellent copper–graphite interface for transmitting heat and stress. The resulting composite has superior thermal conductivity (500 W m^–1 K^–1, 140% of copper), which is in excellent agreement with modeling based on the effective medium approximation. The thermal expansion perpendicular to the graphite platelets drops dramatically from ∼20 ppm K^–1 for graphite and copper separately to 2 ppm K^–1 for the combined structure. We show that this originates from the layered, highly anisotropic structure of graphite combined with residual stress under ambient conditions, that is, strain-engineering of the thermal expansion. Combining excellent thermal conductivity with ultralow thermal expansion results in ideal materials for heat sinks and other devices for thermal management

Nanoplatelet Size to Control the Alignment and Thermal Conductivity in Copper–Graphite Composites

A controlled alignment of graphite nanoplatelets in a composite matrix will allow developing materials with tailored thermal properties. Achieving a high degree of alignment in a reproducible way, however, remains challenging. Here we demonstrate the alignment of graphite nanoplatelets in copper composites produced via high-energy ball milling and spark plasma sintering. The orientation of the nanoplatelets in the copper matrix is verified by polarized Raman scattering and electron microscopy showing an increasing order with increasing platelet size. The thermal conductivity <i>k</i> along the alignment direction is up to five times higher than perpendicular to it. The composite with the highest degree of alignment has a thermal diffusivity (100 mm²s^–1) comparable to copper (105 mm²s^–1) but is 20% lighter. By modeling the thermal properties of the composites within the effective medium approximation we show that (i) the Kapitza resistance is not a limiting factor for improving the thermal conductivity of a copper-graphite system and (ii) copper-graphite-nanoplatelet composites may be expected to achieve a higher thermal conductivity than copper upon further refinement

Protein Handshake on the Nanoscale: How Albumin and Hemoglobin Self-Assemble into Nanohybrid Fibers

Creating and establishing proof of hybrid protein nanofibers (hPNFs), <i>i</i>.<i>e</i>., PNFs that contain more than one protein, is a currently unsolved challenge in bioinspired materials science. Such hPNFs could serve as universal building blocks for the bottom-up preparation of functional materials with bespoke properties. Here, inspired by the protein assemblies occurring in nature, we introduce hPNFs created <i>via</i> a facile self-assembly route and composed of human serum albumin (HSA) and human hemoglobin (HGB) proteins. Our circular dichroism results shed light on the mechanism of the proteins’ self-assembly into hybrid nanofibers, which is driven by electrostatic/hydrophobic interactions between similar amino acid sequences (protein handshake) exposed to ethanol-triggered protein denaturation. Based on nanoscale characterization with tip-enhanced Raman spectroscopy (TERS) and immunogold labeling, our results demonstrate the existence and heterogenic nature of the hPNFs and reveal the high HSA/HGB composition ratio, which is attributed to the fast self-assembling kinetics of HSA. The self-assembled hPNFs with a high aspect ratio of over 100 can potentially serve as biocompatible units to create larger bioactive structures, devices, and sensors