Citrate anticoagulation does not correct cuprophane bioincompatibility as evaluated by the expression of leukocyte surface molecules

BACKGROUND: Citrate, used for the anticoagulation of the extracorporeal dialysis circuit, reduces ionized calcium by chelation and has been claimed to attenuate dialyser membrane bioincompatibility. Dialysis with complement-activating cuprophane membranes is associated with leukopenia which has been related to an increase in adhesion molecule expression on the surface of circulating leukocytes. METHODS: The effect of citrate anticoagulation on the expression of CD11b, CD11c and CD45 on the surface of granulocytes and CD14 on monocytes during haemodialysis with cuprophane membranes, was evaluated by flow cytometric analysis. A comparison of standard heparin vs citrate was performed in 14 chronic haemodialysis patients. During citrate anticoagulation a calcium-free dialysate was used and citrate was infused to obtain a concentration of 4.3 mmol/l blood. The unchallenged 'baseline state' expression of the surface molecules and the increase after ex vivo stimulation with phorbol 12-myristate 13-acetate (delta-PMA) or formyl-methionyl-leucyl-phenylalanine (delta-fMLP) was studied. RESULTS: With heparin, as well as with citrate, a sharp fall in granulocyte and monocyte count was observed after 15 min of dialysis, followed by a recovery at the end of the session. The expression of CD11b, CD11c and CD45 on granulocytes increased markedly during cuprophane dialysis with a peak at 15 min; there were no differences in response between heparin and citrate anticoagulation. Delta-PMA and delta-fMLP for CD45, CD11c and CD14 showed a decrease during cuprophane dialysis vs t0; again there were no differences between heparin and citrate. CONCLUSION: We conclude that the use of citrate was not associated with reduced leukocyte activation as measured by the expression of surface molecules during cuprophane dialysis and that no effect on dialysis leukocytopenia could be registered.     

Developing a research unit within a hospital social work department

This article describes the establishment of a research unit as an integral part of a hospital social work department on the basis of the authors' experience in a cancer center over a 13-year period. Methods are described for building support within the institution, for the process of initiating the unit, for deciding on study topics, and finally for bridging the gap between clinical and research staff. The evolution of the relationship between clinical and research staff was characterized by four different phases: curiosity, competitiveness, cooperation, and collaboration. A childhood bereavement project is used to exemplify the developmental processes and the ongoing interaction of research and clinical staff. The professional practice of all staff benefited from the increased academic rigor and productivity, although some staff remained unconvinced of the value of such a major research effort. The benefits and costs of the unit are also discussed.     

Ability of Selected Lactic Acid Bacteria to Ferment a Pearl Millet–Soybean Slurry to Produce Gruels for Complementary Foods for Young Children

Abstract: To assess the ability of lactic acid bacteria to improve some nutritional characteristics of the pearl millet–soybean slurry to prepare complementary foods for young children in African countries, inoculation was performed using strains previously selected for their ability to hydrolyse starch, phytate, or α-galactooligosaccharides (α-GOS). For the sake of comparison with the action of a natural microflora, fermentation was also performed by back slopping inoculation, that is, with a sample obtained from spontaneously fermented traditional pearl millet slurry obtained from a small scale processing unit in Burkina Faso (Ouagadougou). Starter cultures thrived on the slurry as shown by counts on MRS agar, TTGE fingerprints, and fermentation patterns. The fermentation of precooked slurries inoculated by back slopping or with mixed cultures containing the amylolytic strain Lb. plantarum A6 enabled partial starch hydrolysis. Corresponding gruels had a suitable consistency for young child feeding at high dry matter content, and a high energy density: 88.7 ± 4.2 and 75.8 ± 5.1 kcal/100 g of sweetened gruel, for the gruels inoculated by back slopping or with Lb. plantarum A6, respectively. Unexpectedly, no decrease in phytates was observed in any of the experiments, suggesting the presence of one or more inhibitory compounds in soybean. Furthermore, preprocessing conditions before fermentation affect the carbohydrate composition of slurry and have a more profound effect than fermentation on the reduction of the α-GOS content. Practical Application: This research aims to investigate the capacity of selected lactic acid bacteria to produce in a bioprocess high energy density and nutritious gruels for complementary feeding of young children from an African cereal (pearl millet) mixed with soybean.     

Enhancement-Mode PEDOT:PSS Organic Electrochemical Transistors Using Molecular De-Doping

Organic electrochemical transistors (OECTs) show great promise for flexible, low-cost, and low-voltage sensors for aqueous solutions. The majority of OECT devices are made using the polymer blend poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), in which PEDOT is intrinsically doped due to inclusion of PSS. Because of this intrinsic doping, PEDOT:PSS OECTs generally operate in depletion mode, which results in a higher power consumption and limits stability. Here, a straightforward method to de-dope PEDOT:PSS using commercially available amine-based molecular de-dopants to achieve stable enhancement-mode OECTs is presented. The enhancement-mode OECTs show mobilities near that of pristine PEDOT:PSS (≈2 cm² V⁻¹ s⁻¹) with stable operation over 1000 on/off cycles. The electron and proton exchange among PEDOT, PSS, and the molecular de-dopants are characterized to reveal the underlying chemical mechanism of the threshold voltage shift to negative voltages. Finally, the effect of the de-doping on the microstructure of the spin-cast PEDOT:PSS films is investigated.     

SAR distribution in human beings when using body-worn RF transmitters

This study analyzes the exposure of the human torso to electromagnetic fields caused by wireless body-mounted or handheld devices. Because of the frequency and distance ranges from 30-5800 MHz and 10 to 200 mm, respectively, both near-field and far-field effects are considered. A generic body model and simulations of anatomical models are used to evaluate the worst case tissue composition with respect to the absorption of electromagnetic energy. Both standing wave effects and enhanced coupling of reactive near-field components can lead to a specific absorption rate (SAR) increase in comparison to homogeneous tissue. In addition, the exposure and temperature increase of different inner organs is assessed. With respect to compliance testing, the observed SAR enhancement may require the introduction of a multiplication factor for the spatial peak SAR measured in the liquid-filled phantom in order to obtain a conservative exposure assessment. The observed tissue heating at the body surface under adiabatic conditions can be significant, whereas the temperature increase in the inner organs turned out to be negligible for the cases investigated.     

Internal Nitridation of Nickel-Base Alloys. Part II. Behavior of Quaternary Ni-Cr-Al-Ti Alloys and Computer-Based Description

Whereas in Part I of this study the process ofinternal nitridation was described for binary andternary alloys within the Ni-Cr-Al-Ti system, this partfocuses on quaternary Ni-Cr-Al-Ti alloys, which are similar to commercial Ni-base alloys used inhigh-temperature applications regarding their chemicalcompositions. These alloys can simultaneously form twodifferent nitride-precipitation zones consisting of TiN and AlN. In order to quantify thenitridation process, thermogravimetric measurements inan oxygen-free nitrogen atmosphere in the temperaturerange 800-1100°C were carried out and supplemented by extensive microstructural studies. Whilesingle-nitride internal nitridation can easily bedescribed by Wagner's theory of internal oxidation,modeling of the more complex internal-precipitationreactions that involves more than one nitride requires anumerical treatment of both the diffusion and thethermochemical processes in the alloy. For this purpose,a computer simulation was developed in which the commercial thermodynamic software ChemApp iscombined with a finite-difference diffusion calculation.It was shown that this calculation technique can beapplied successfully to quantitatively describe the internal-nitridation process of theNi-Cr-Al-Ti model alloys used in this study.