Nanostructured Cobalt Doped Barium Strontium Titanate Thin Films with Potential in CO2 Detection.

In this work, (Ba0.75Sr0.25) (Ti0.95Co0.05) O3 perovskite nanostructured material, denoted subsequently as Co-doped BaSrTiO3, was synthesized in a one-step process in hydrothermal conditions. The obtained powder was heat-treated at 800 °C and 1000 °C, respectively, in order to study nanostructured powder behavior during thermal treatment. The Co-doped BaSrTiO3 powder was pressed into pellets of 5.08 cm (2 inches) then used for thin film deposition onto commercial Al2O3 substrates by RF sputtering method. The microstructural, thermal, and gas sensing properties were investigated. The electrical and thermodynamic characterization allowed the evaluation of thermodynamic stability and the correlation of structural features with the sensing properties revealed under real operating conditions. The sensing behavior with respect to the temperature range between 23 and 400 °C, for a fixed CO2 concentration of 3000 ppm, highlighted specific differences between Co-doped BaSrTiO3 treated at 800 °C compared to that treated at 1000 °C. The influence of the relative humidity level on the CO2 concentrations and the other potential interfering gases was also analyzed. Two possible mechanisms for CO2 interaction were then proposed. The simple and low-cost technology, together with the high sensitivity when operating at room temperature corresponding to low power consumption, suggests that Co-doped BaSrTiO3 has a good potential for use in developing portable CO2 detectors.

Trigger points--ultrasound and thermal findings.

RATIONALE: Muscle pain can be elicited by any irritation of the nociceptors in the muscle or central sensitization in the central nervous system. The most frequently described muscle pain syndromes are myofascial pain syndrome and fibromyalgia syndrome. Myofascial pain syndrome has a more localized manifestation, the trigger points. OBJECTIVE: If there is a correlation between the clinical findings, the ultrasound examination and the thermal pattern of trigger points exist. MATERIAL AND METHOD: The presence of trigger points can be identified by using clinical criteria. An ultrasound examination was performed to evaluate the trigger point dimensions. The ultrasound showed an ellipsoidal hypoechogenic area in the muscle. A thermography of the low back region was performed in order to observe the thermal pattern of the area. RESULTS: Trigger points are represented by a higher temperature area surrounded by a cooler area, probably caused by a deficit in the blood flow around those points. DISCUSSION: Infrared thermography could be a great asset for the monitoring of neuromusculoskeletal disorders and their dynamics, as well as an important aid for the initial diagnosis of conditions associated with tissue temperature alterations.

Possible errors in the calculation of cell-binding parameters exemplified by the analysis of the IgG-Fc receptor system.

The binding parameters of monomeric and polymeric (immune complex with a molecular weight of 500,000 daltons) rabbit IgG to homologous Fc receptor-bearing alveolar macrophages were estimated, using corrected values for IgG and cell concentrations. Considering the maximum percentage of monomeric IgG binding to cells (2.7%) and the maximum percentage of cells binding monomeric IgG (32%) instead of the IgG and cell concentrations in the initial reaction mixture, a 36-fold increase of the equilibrium constant (K) (from 0.6 x 10(6) L/M to 21.3 x 10(6) L/M) and a 3-fold increase of the maximum number of IgG molecules able to bind to a single cell (n) (from 7.8 x 10(5) to 23.7 x 10(5] were registered. Since more than 60% of the polymeric IgG is bound to 46% of the macrophage population, the values of K (from 10.8 x 10(6) L/M to 15.6 x 10(6) L/M) and n (from 4.3 x 10(5) to 9.4 x 10(5] are only doubled by using the corrected values for IgG and cell concentrations. It results that the cytophilic fraction of the monomeric IgG, representing only 2.7% of total IgG, has a slightly higher affinity for the Fc receptors than the polymeric IgG. By considering the actual number of macrophages which bind IgG it is evident that the number of Fc receptors per cell is higher than that determined by the usual procedure which does not take into account cellular heterogeneity.