Searching for biological feedstock material: 3D printing of wood particles from house borer and drywood termite frass.

Frass (fine powdery refuse or fragile perforated wood produced by the activity of boring insects) of larvae of the European house borer (EHB) and of drywood termites was tested as a natural and novel feedstock for 3D-printing of wood-based materials. Small particles produced by the drywood termite Incisitermes marginipennis and the EHB Hylotrupes bajulus during feeding in construction timber, were used. Frass is a powdery material of particularly consistent quality that is essentially biologically processed wood mixed with debris of wood and faeces. The filigree-like particles flow easily permitting the build-up of wood-based structures in a layer wise fashion using the Binder Jetting printing process. The quality of powders produced by different insect species was compared along with the processing steps and properties of the printed parts. Drywood termite frass with a Hausner Ratio HR = 1.1 with ρBulk = 0.67 g/cm3 and ρTap = 0.74 g/cm3 was perfectly suited to deposition of uniformly packed layers in 3D printing. We suggest that a variety of naturally available feedstocks could be used in environmentally responsible approaches to scientific material sciences/additive manufacturing.

The use of Do-Not-Resuscitate-Order equivalents in pediatric palliative care medicine in Germany.

BACKGROUND: In the last years, the structure of Pediatric Palliative Care in Germany has developed more and more. Since 2007, there is a legal claim for a specialized palliative care in German which also applies to children. Therefore, the need of an advance care planning for children is frequently discussed. In Germany, a written advance is judicially approved only when the person concerned is of full age, intentions to change this legal ground are going on. Nevertheless in many institutions involved in pediatric palliative care standard forms similar to an advance patient directive are used, especially since 2009 when a Do-Not-Resuscitate-Order (DNR-Order) equivalent for children was published on which many German pediatric medical societies had agreed. METHODS: To get an overview which DNR-Order equivalents are actually used in pediatric palliative care in Germany we sent a questionnaire with 10 items to 174 institutions that are involved in pediatric oncological palliative care between August 2012 and October 2013. RESULTS: Only 46.9% of replying institutions used the DNR-Order equivalent for children approved by many German pediatric societies. When asked for optimizing such an advance patient directive for minors it was mostly suggested to include always a protocol of the consenting talk, an individualized treatment algorithm of all therapeutic options (not only emergency measures) in the palliative setting, and a more detailed information about the patient's current palliative situation. CONCLUSIONS: All collected data were summarized within a suggestion for a new advance pediatric oncological care planning standard form for minors in Germany.

Microstructure and Deformation Response of TRIP-Steel Syntactic Foams to Quasi-Static and Dynamic Compressive Loads.

The implementation of hollow S60HS glass microspheres and Fillite 106 cenospheres in a martensitically transformable AISI 304L stainless steel matrix was realized by means of metal injection molding of feedstock with varying fractions of the filler material. The so-called TRIP-steel syntactic foams were studied with respect to their behavior under quasi-static compression and dynamic impact loading. The interplay between matrix material behavior and foam structure was discussed in relation to the findings of micro-structural investigations, electron back scatter diffraction EBSD phase analyses and magnetic measurements. During processing, the cenospheres remained relatively stable retaining their shape while the glass microspheres underwent disintegration associated with the formation of pre-cracked irregular inclusions. Consequently, the AISI 304L/Fillite 106 syntactic foams exhibited a higher compression stress level and energy absorption capability as compared to the S60HS-containing variants. The α ′ -martensite kinetic of the steel matrix was significantly influenced by material composition, strain rate and arising deformation temperature. The highest ferromagnetic α ′ -martensite phase fraction was detected for the AISI 304L/S60HS batches and the lowest for the TRIP-steel bulk material. Quasi-adiabatic sample heating, a gradual decrease in strain rate and an enhanced degree of damage controlled the mechanical deformation response of the studied syntactic foams under dynamic impact loading.

Modulation infrared thermometry of caloric effects at up to kHz frequencies.

We present a novel non-contact method for the direct measurement of caloric effects in low volume samples. The adiabatic temperature change ΔT of a magnetocaloric sample is very sensitively determined from thermal radiation. Rapid modulation of ΔT is induced by an oscillating external magnetic field. Detection of thermal radiation with a mercury-cadmium-telluride detector allows for measurements at field frequencies exceeding 1 kHz. In contrast to thermoacoustic methods, our method can be employed in vacuum which enhances adiabatic conditions especially in the case of small volume samples. Systematic measurements of the magnetocaloric effect as a function of temperature, magnetic field amplitude, and modulation frequency give a detailed picture of the thermal behavior of the sample. Highly sensitive measurements of the magnetocaloric effect are demonstrated on a 2 mm thick sample of gadolinium and a 60 µm thick Fe80B12Nb8 ribbon.

Effects of Cu doping on the electronic structure and magnetic properties of MnCo2O4 nanostructures.

Reported here are the results and their analysis from our detailed investigations of the effects of Cu doping ([Formula: see text]) on the electronic structure and magnetic properties of the spinel [Formula: see text]O4. A detailed comparison is given for the [Formula: see text] and [Formula: see text] cases for both the bulk-like samples and nanoparticles. The electronic structure determined from x-ray photoelectron spectroscopy and Rietveld analysis of x-ray diffraction patterns shows the structure to be: ([Formula: see text])A [Formula: see text] [Formula: see text] [Formula: see text]]B [Formula: see text] i.e. [Formula: see text] substitutes for [Formula: see text] on the octahedral B-sites. For the bulk samples, the ferrimagnetic [Formula: see text] K for [Formula: see text] is lowered to [Formula: see text] K for the [Formula: see text] sample, this decrease being due to the effect of Cu doping. For the nanosize [Formula: see text] ([Formula: see text]) sample, the lower [Formula: see text] K ([Formula: see text] K) is observed using [Formula: see text] analysis, this lowering being due to finite size effects. For [Formula: see text], fits of dc paramagnetic susceptibility data of [Formula: see text] versus T in nanosize samples to the Néel expression are used to determine the exchange interactions between the A and B sites with exchange constants: [Formula: see text] K (4.1 K), [Formula: see text] K (16.3 K) and [Formula: see text] K (13.8 K) for [Formula: see text]. The temperature dependence of ac susceptibilities [Formula: see text] and [Formula: see text] at different frequencies shows that in bulk samples of [Formula: see text] and [Formula: see text], the transition at T C is the normal second order transition. But for the nanosize [Formula: see text] and 0.2 samples, analysis of the ac susceptibilities shows that the ferrimagnetic transition at T C is followed by a re-entrant spin-glass transition at lower temperatures [Formula: see text] K (138 K) for [Formula: see text] ([Formula: see text]). Analysis of the ac susceptibilities, [Formula: see text] and [Formula: see text], versus T data is done in terms of two scaling laws: (i) Vogel-Fulcher law [Formula: see text] [Formula: see text]; and (ii) power law of critical slowing-down [Formula: see text]. These fits confirm the existence of glassy behavior below T SG with the parameters [Formula: see text] (8.91), [Formula: see text] (9.6 × 10[Formula: see text]) and [Formula: see text] K (∼138 K) for the samples [Formula: see text] (0.2), with similar results obtained for other samples. The linear behavior of the peak maximum in [Formula: see text] versus [Formula: see text] (AT-line) further supports the existence of glassy states in nanosize samples. For [Formula: see text], the temperature and composition dependence of the hysteresis loop parameters are investigated; all the samples with x ⩾ 0.1 have the coercivity H C and remanence [Formula: see text]. Since the results reported here in these nanostructures are significantly different from those in bulk [Formula: see text] [Formula: see text], further investigations of their magnetic structures using neutron diffraction are warranted.

Highly Concentrated Alginate-Gellan Gum Composites for 3D Plotting of Complex Tissue Engineering Scaffolds.

In tissue engineering, additive manufacturing (AM) technologies have brought considerable progress as they allow the fabrication of three-dimensional (3D) structures with defined architecture. 3D plotting is a versatile, extrusion-based AM technology suitable for processing a wide range of biomaterials including hydrogels. In this study, composites of highly concentrated alginate and gellan gum were prepared in order to combine the excellent printing properties of alginate with the favorable gelling characteristics of gellan gum. Mixtures of 16.7 wt % alginate and 2 or 3 wt % gellan gum were found applicable for 3D plotting. Characterization of the resulting composite scaffolds revealed an increased stiffness in the wet state (15%⁻20% higher Young's modulus) and significantly lower volume swelling in cell culture medium compared to pure alginate scaffolds (~10% vs. ~23%). Cytocompatibility experiments with human mesenchymal stem cells (hMSC) revealed that cell attachment was improved-the seeding efficiency was ~2.5⁻3.5 times higher on the composites than on pure alginate. Additionally, the composites were shown to support hMSC proliferation and early osteogenic differentiation. In conclusion, print fidelity of highly concentrated alginate-gellan gum composites was comparable to those of pure alginate; after plotting and crosslinking, the scaffolds possessed improved qualities regarding shape fidelity, mechanical strength, and initial cell attachment making them attractive for tissue engineering applications.