Oxygen consumption,acidification and migration capacity of human primary osteoblasts within a three-dimensional tantalum scaffold

A major clinical problem within synthetic, large-scaled scaffolds is the insufficient nutrient supply resulting in inhomogeneous cell proliferation and differentiation. The aim of this study was to analyse pH value, oxygen consumption and migration of human osteoblasts within a 3D tantalum scaffold, clinically used for larger bone defects. After 24 h the oxygen concentration within the scaffold decreased significantly and remained low during incubation. Monitoring of the pH value inside the tantalum scaffold showed a slightly acidification under static culture conditions. However, cell migration within the 3D scaffold was detected. Hence, in clinical application it can be assumed that porous tantalum scaffolds can be settled by osteoblasts under critical oxygen and nutrient supply. In general, monitoring of cell migration, oxygen consumption and acidification can be a suitable instrument for creating advanced 3D bone scaffolds.     

Diagnosing a common rater halo effect using the polytomous Rasch model

The 'halo effect' may be unique to different raters or common to all raters. When common to all raters, halo is not detectable through standard fit indices of the three-facet Rasch model used to account for differences in rater severities. Using a formulation of halo as a violation of local independence, a halo effect common to all raters is simulated and shown to be diagnosable through contrasts between two-facet stack and rack Rasch analyses. In the former, the thresholds are clustered and the distribution of persons is multimodal; in the latter, all thresholds are close together and the distribution of persons is unimodal. In the former, the scale is stretched, and the person separation inflated, relative to the latter.     

Effects of increasing internal end-point temperatures on physicochemical and sensory properties of meat: A review

Although many efforts have been made to improve and control the eating quality of meat, there is still high variability in palatability, which may ultimately result in customer dissatisfaction. Beef meat is especially intricate to study since consumers have specific preferences for degrees of doneness. The degrees of doneness in beef is known to affect its physicochemical properties and have a subsequent effect on palatability. Nevertheless, an in-depth investigation into the exact changes that occur with increasing internal end-point temperatures of meat is yet to be explored. With researchers implementing various cooking methods and cooking conditions (i.e., sample preparation and internal end-point temperatures), the results of studies are often impossible to compare. This review provides an overview of the various benefits and drawbacks of the cooking methods commonly used at home, in commercial enterprises, and research on meat. Furthermore, the physicochemical changes in meat with increasing degrees of doneness are discussed in detail with considerations of the subsequent changes in the sensory properties of meat.     

The Microbial Contamination,Toxicity and Quality of Turned and Unturned Outdoor Floor Malted Sorghum

Turned and unturned outdoor floor malted sorghum were studied for their total microbial contamination, nature and extent of contamination by moulds, cytotoxicity (IC₅₀) and quality in terms of diastatic power (DP). The presence of aflatoxins, fumonisins, deoxynivalenol and zearalenone were also investigated. Total microbial counts were high (10⁷–10⁸ cfu/g) in both turned and unturned samples. All samples showed contamination by different moulds, with the dominant being Mucor species, Rhizopus oryzae, Fusarium moniliforme and Phoma sorghina as well as Aspergillus flavus and Alternaria alternata. The latter four are known for producing mycotoxins. Malt samples had very low cytotoxicity (IC₅₀ from 62.5 to >1000 kg/kg), though all contained fumonisins, deoxynivalenol and zearalenone at levels of <0.25–2 μg/g, 15–20 and 10–15 μg/kg, respectively. Malt DP was generally lower in turned samples compared to unturned samples probably because the heat conserved in the latter ensured better germination conditions. Overall, turning during germination did not affect the microbial load, mould population and levels of deoxynivalenol and zearalenone in sorghum malt but decreased sorghum malt DP. Thus, alternative methods of controlling the sorghum malt microbial load should be sought.     

Vakuumfüllverfahren bei Quecksilberthermometern

Since about 60 years vacuum is used to fill thermometers with mercury. The knowledge of the evacuation time and the influence of the bakeout conditions for each type of thermometers was found empirically. By means of miniaturized pressure sensors the progress of evacuation and the pressure necessary for filling the thermometers with mercury without air bubbles was measured. In the range from 0,05 mbar small filament lamps were used as Pirani gauges. The software for the calculation of evacuation curves for thermometers was developed. The calculated evacuation curves could be fitted very well to the experimental results. The evacuation curves for some current types of thermometers were calculated by means of the received parameters. It was found that the evacuation time for a bubble free filling of thermometers with mercury depend on the diameter and length of the capillary, the volume of the thermometer bulb and the bakeout conditions.     

Inositolpolyphosphates and their binding proteins--a short review

Behavioral studies were conducted in rats administered a selective D3 agonist, 7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) or 4aR, 10bR-(+)-trans-3,4,4a,10b-tetrahydro-4-propyl-2H,5H-[1] benzopyrano[4,3-b]-1,4-oxazin-9-ol (PD 128907). Both drugs induced disruption of huddling behavior in rats at doses that did not produce hyperlocomotion. The effects of the D3 agonists were dependent upon dosage and time after administration. These results suggest that D3 receptors are concerned with social interaction in rats.     

The effect of bonded and nonbonded posts on the fracture resistance of dentin]

This in vitro study determined the effect of bonded and non-bonded cast, serrated, tin plated, parallel gold posts on the fracture resistance of surrounding dentine walls. Specimens were divided into two groups. One group's posts were luted with zinc phosphate cement and the other group's posts were tin-plated and adhesively bonded with an adhesive resin cement. Three different dentine wall thicknesses, namely 0.5 mm, 0.75 mm and 1.0 mm were prepared, subdividing the specimens of each main group into three subgroups. Specimens were subjected to a 50 degrees oblique force. The force required to fracture the dentinal walls was registered. There was no statistically significant differences in the fracture resistance of dentine with the two different cements or of the different dentine wall thicknesses.     

Influence of sandwinds on the durability of polyethylene greenhouse aged under sub-saharan climatic conditions

Sandwinds have been simulated with an apparatus developed in our laboratory. Infra red and UV visible spectroscopies, contact angle and interferential microscopy investigations have been performed on untreated polyethylene film sample and on samples submitted at 40 °C to a simulated sandwind for times up to 4 hours. The surface roughness is modified, leading to drastic decrease of the ultra-violet visible light transmission. This phenomenon is due to the presence of small sand particles inlaid in the sample surface and due to surface erosion. In the time range of our experiments, no chemical action due to the sandwind is observed. Electronic Publication     

Ultraviolet Raman spectra and cross-sections of the G-series nerve agents

Ultraviolet (UV) Raman spectroscopy is being applied to the detection of chemical agent contamination of natural and man-made surfaces. In support of these efforts, we have measured the UV Raman signatures of the G-series nerve agents GA (tabun), GB (sarin), GD (soman), GF (cyclosarin), and the agent simulant diisopropyl methylphosphonate (DIMP) at 248 nm and 262 nm, as well as taking their UV Raman and UV absorption cross-sections. Of these chemicals, only GA exhibits any significant pre-resonance enhancement. We also show that reduction of the excitation wavelength from 262 nm to 248 nm effectively shifts the Raman spectrum away from a substantial sample fluorescence background, implying a significant improvement in detection capability.     

Modell zur Analyse des knöchernen Anwachsverhaltens auf bioaktiv beschichteten Implantatoberflächen

Model to analyse the bone on‐growth on bioactive coated implant surfaces Especially on the field of bone regeneration, transient and permanent implants are an important method of therapy in the Orthopaedic Surgery. In this context, bioactive surfaces on metallic implants provide an improved contact to the surrounding bone. The goal of our study was to establish an in‐vitro test system to evaluate the on‐growth of bone‐derived cells on different surface coatings. Therefore, we invented a special kind of clamps made of commercially‐pure (c‐p) titanium and blasted with hydroxyapatite particles followed by electrochemically coating with calcium phosphate (BONIT®‐HA, BONIT®). Definite pieces of human cancellous bone were attached to these clamps, inserted onto tissue culture plates and cultivated in DMEM for ten days. Finally, the contact area between human cancellous bone and the implant surface was analyzed and the spreading of osteoblast‐like cells evaluated by scanning electron microscopy (SEM). A well‐spread morphology of bone cells was observed on the implant surfaces coated with calcium phosphate (CaP). In comparison the clamps without CaP coatings showed only a marginal growth of bone cells on the clamp surface. The presented newly in‐vitro test setup using titanium clamps coated with bioactive layers attached to human cancellous bone represents a well‐functioning model for qualitative evaluation of bone on‐growth.