A Single-Cell Raman Spectroscopy Analysis of Bone Marrow Mesenchymal Stem/Stromal Cells to Identify Inter-Individual Diversity

The heterogeneity of stem cells represents the main challenge in regenerative medicine development. This issue is particularly pronounced when it comes to the use of primary mesenchymal stem/stromal cells (MSCs) due to a lack of identification markers. Considering the need for additional approaches in MSCs characterization, we applied Raman spectroscopy to investigate inter-individual differences between bone marrow MSCs (BM-MSCs). Based on standard biological tests, BM-MSCs of analyzed donors fulfill all conditions for their characterization, while no donor-related specifics were observed in terms of BM-MSCs morphology, phenotype, multilineage differentiation potential, colony-forming capacity, expression of pluripotency-associated markers or proliferative capacity. However, examination of BM-MSCs at a single-cell level by Raman spectroscopy revealed that despite similar biochemical background, fine differences in the Raman spectra of BM-MSCs of each donor can be detected. After extensive principal component analysis (PCA) of Raman spectra, our study revealed the possibility of this method to diversify BM-MSCs populations, whereby the grouping of cell populations was most prominent when cell populations were analyzed in pairs. These results indicate that Raman spectroscopy, as a label-free assay, could have a huge potential in understanding stem cell heterogeneity and sorting cell populations with a similar biochemical background that can be significant for the development of personalized therapy approaches.     

Identification of buckwheat (Fagopyrum esculentum Moench) aroma compounds with GC–MS

Buckwheat has a strong characteristic aroma, but its phytochemical background has not yet been fully elucidated. The aims of this study were identification and quantification of individual compounds responsible for the buckwheat aroma. Volatiles from a freshly ground buckwheat flour were extracted by different methods: direct extraction with petroleum ether, pentane or methanol, distillation with Clevenger apparatus and a headspace solid-phase microextraction method. The extracts were analysed by GC–MS with electron ionisation. Compounds were identified by MS and by comparison of retention times with reference compounds. Direct extraction with methanol and distillation proved to be very efficient. In these extracts twenty-five and thirty-five compounds were identified, respectively. The first extract contained more hydrophilic compounds and the latter more volatile compounds. Most of the compounds were quantified and their odour activity value (OAV) calculated. Only two compounds (salicylaldehyde and phenylacetaldehyde) were found in both extracts. The compounds with the highest contribution to the buckwheat aroma were: 2,5-dimethyl-4-hydroxy-3(2H)-furanone, (E,E)-2,4-decadienal, phenylacetaldehyde, 2-methoxy-4-vinylphenol, (E)-2-nonenal, decanal, hexanal and salicylaldehyde (2-hydroxybenzaldehyde).     

Novel Low-Temperature Synthesis of Disodium Dimolybdate by Ultrasonic Spray Pyrolysis

A new method for the synthesis of disodium dimolybdate (Na₂Mo₂O₇) in the process of ultrasonic spray pyrolysis using acidified aqueous solutions of thermodynamically stable molybdenum (VI) oxide clusters as a precursor is described. Na₂Mo₂O₇ particles were collected in alcohols (ethanol, 2-propanol, isobutyl alcohol), and ultracentrifugation was used to isolate solid material from solution. Scanning electron microscopy revealed the formation of uniform spherical Na₂Mo₂O₇ particles with an average diameter of about 0.25 μm. The X-ray diffraction analysis undoubtedly confirmed the formation of orthorhombic Na₂Mo₂O₇ for samples synthesized at a temperature as low as 300°C.     

Motor cortex lesions do not affect learning or performance of the eyeblink response in rabbits.

The possible modulatory role of motor cortex in classical conditioning of the eyeblink response was examined by ablating anterior neocortex in rabbits and training them with an auditory conditioned stimulus (CS) and an airpuff unconditioned stimulus (US) in either a delay (Experiment 1) or a trace (Experiment 2) conditioning paradigm. Topographic measures such as amplitude and onset latency were assessed during conditioning sessions for conditioned responses (CRs) and on separate test days for unconditioned responses (URs) by using a range of US intensities. No lesion effects were observed for learning or performance measures in acquisition or retention of either delay or trace conditioning. During trace conditioning, lesioned rabbits did, however, exhibit a trend toward impairment and demonstrated significantly longer CR latencies. Damage to motor and frontal cortex does not significantly affect eyeblink response performance or learning in either a delay or a trace conditioning paradigm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental study and thermodynamic remodeling of the Bi–Cu–Ni system

Phase equilibria in the Bi–Cu–Ni ternary system have been studied using differential thermal analysis (DTA) as well as by using the calculation of the phase diagram (CALPHAD) method. Literature experimental phase equilibria data and DTA results from this study were used for thermodynamic modeling of the Bi–Cu–Ni ternary system. Isothermal sections at 300, 400, and 500 °C, vertical sections from bismuth corner with molar ratio Cu:Ni=1/3, 1/1 and 3/1 and vertical section at 40 at.% Cu were calculated and compared with corresponding experimental results. Reasonable agreement between the calculated and experimental data was observed in all cases.     

Experimental investigation and thermodynamic prediction of the Ni-Pb-Sb phase diagram

The phase diagram of the ternary Ni-Pb-Sb system was investigated experimentally by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) methods, and predicted using the calculation of phase diagrams (CALPHAD) method. The phase transition temperatures of alloys along three predicted vertical sections of the Ni-Pb-Sb ternary system, with molar ratio Ni:Sb=1:3, Ni:Pb=1, and x(Sb)=0.6, were measured by DSC. The predicted isothermal section at 700 °C was compared with the results of the SEM-EDS analysis in this work.     

Perturbation of solutions of ordinary linear homogeneous differential equations of the second order

In this paper we give a method for peturbation of solutions of linear homogeneous differential equation of the second order.     

Microsized fayalite Fe2SiO4 as anode material: the structure,electrochemical properties and working mechanism

Journal of Electroceramics - Fayalite Fe2SiO4 is synthesized by the solid-state reaction without ball milling. The obtained powder is further structurally and electrochemically examined. Field...