Search results for "printing"

Ordered networks of rat hippocampal neurons attached to silicon oxide surfaces.

2001

The control of neuronal cell position and outgrowth is of fundamental interest in the development of applications ranging from cellular biosensors to tissue engineering. We have produced rectangular networks of functional rat hippocampal neurons on silicon oxide surfaces. Attachment and network formation of neurons was guided by a geometrical grid pattern of the adhesion peptide PA22-2 which matches in sequence a part of the A-chain of laminin. PA22-2 was applied by contact printing onto the functionalised silicon oxide surface and was immobilised by hetero-bifunctional cross-linking with sulfo-GMBS. Geometric pattern matching was achieved by microcontact printing using a polydimethylsiloxa…

Spot compliant neuronal networks by structure optimized micro-contact printing

2001

Neuronal cell growth in vitro can be controlled with micropatterned structures of extracellular matrix proteins such as laminin. This technique is a powerful tool for studying neuronal cell function in order to increase experimental reproducibility and to specifically design innovative experimental setups. In this paper the correlation between the structural dimensions of the ECM pattern and the shape of the resulting cellular network is analyzed. The aim of the present study was to position neuronal cell bodies as precisely as possible and to induce directed cell differentiation. PCC7-MzN cells were cultured on laminin patterns. The line width, node size and gap size in-between cell adhesi…

Oblique collision and evolution of large-scale transcurrent shear zones in the Kaoko belt, NW Namibia

2005

Abstract Early structures in the central part of the Kaoko orogenic belt of NW Namibia suggest that the initial stage of collision was governed by underthrusting of the medium-grade Central Kaoko zone below the high-grade Western Kaoko zone, resulting in the development of an inverted metamorphic gradient. In the Western zone, early structures were overprinted by a second phase of deformation, which is associated with localization of the transcurrent Puros shear zone along the contact between the Western and Central zones. During this second phase, extensive partial melting and intrusion of ∼550 Ma granitic bodies occurred in the high-grade Western zone. In the Central zone, the second phas…

The accuracy of three-dimensional rapid prototyped surgical template guided anterior segmental osteotomy

2019

Background Surgical guiding templates provided a reliable way to transfer the simulation to the actual operation. However, there was no template designed for anterior segmental osteotomy so far. The study aimed to introduce and evaluate a set of 3D rapid prototyping surgical templates used in anterior segmental osteotomy. Material and Methods From August 2015 to August 2017, 17 patients with bimaxillary protrusions were recruited and occlusal-based multi-sectional templates were applied in the surgeries. The cephalometric analysis and 3D superimposition were performed to evaluate the differences between the simulations and actual post-operative outcomes. The patients were followed-up for 12…

Effect of bioglass on growth and biomineralization of SaOS-2 cells in hydrogel after 3D cell bioprinting.

2014

We investigated the effect of bioglass (bioactive glass) on growth and mineralization of bone-related SaOS-2 cells, encapsulated into a printable and biodegradable alginate/gelatine hydrogel. The hydrogel was supplemented either with polyphosphate (polyP), administered as polyP • Ca2+-complex, or silica, or as biosilica that had been enzymatically prepared from ortho-silicate by silicatein. These hydrogels, together with SaOS-2 cells, were bioprinted to computer-designed scaffolds. The results revealed that bioglass (nano)particles, with a size of 55 nm and a molar ratio of SiO2 : CaO : P2O5 of 55 : 40 : 5, did not affect the growth of the encapsulated cells. If silica, biosilica, or polyP …

3D spectral imaging with synchrotron Fourier transform infrared spectro-microtomography

2013

We report Fourier transform infrared spectro-microtomography, a nondestructive three-dimensional imaging approach that reveals the distribution of distinctive chemical compositions throughout an intact biological or materials sample. The method combines mid-infrared absorption contrast with computed tomographic data acquisition and reconstruction to enhance chemical and morphological localization by determining a complete infrared spectrum for every voxel (millions of spectra determined per sample).

Comparative analysis of short tandem repeats and single nucleotide polymorphisms on the Y-chromosome in Germans, Chinese and Thais.

2003

We have typed genomic DNA samples from 95 individuals from Western Germany, 78 individuals from Bangkok/Thailand and 56 individuals from Chengdu/China for 11 Y-chromosomal diallelic polymorphisms and eight short tandem repeat (STR) systems. For single nucleotide polymorphism (SNP) analysis, a rapid method was applied using the single base extension technology (minisequencing) in combination with capillary electrophoresis. PCR products for SRY-8299, Tat, SRY2627, 92R7, SRY1532, M9, M13, M17/M19 and M20 were pooled and used as templates for the commercially available SNaPshot kit. In addition to these ten SNPs we also tested the Y-chromosomal diallelic Alu repeat insertion DYS287 (YAP) by aga…

Enantiomer Separations Using Designed Imprinted Chiral Phases

2003

Influence of template basicity and hydrophobicity on the molecular recognition properties of molecularly imprinted polymers

1996

Abstract Triazine herbicides were used as model templates for a basic study of the molecular recognition process in imprinted polymers. Five structurally related triazine herbicides (atrazine, ametryn, cyanazine, prometryn and terbutylazine) that differ in basicity and hydrophobicity were imprinted. Chromatographic evaluation of the resulting materials in an aqueous-poor mobile phase showed that the selectivity for the template increased with its Bronsted basicity whereas it did not correlate with template hydrophobicity. Thus, the highest and lowest affinity and selectivity for the template was observed using the ametryn-imprinted (p K a =4.1) and the cyanazine-imprinted polymers (p K a =1…

Molecularly imprinted polymer-based device for field collection of oral fluid samples for cocaine identification.

2020

In this paper, a low-cost, rapid, easy, and potentially portable tool for the identification of cocaine and its semi-quantitative determination in oral fluid has been proposed. A field collection device has been designed, based on a cotton pad with an indicator and a molecularly imprinted polymer (MIP) sorbent, to selective retain cocaine from oral fluid components. After sample collection, cocaine is transferred by using phosphate buffer to the MIP and then eluted with 2-propanol. The obtained extract is analysed by ion mobility spectrometry (IMS), providing a cut-off value of 20 µg L-1 that identifies 100 % true-positive and 95 % true-negative samples. The MIP-IMS procedure has been valid…