Role of densitometric examination in diagnosis of osteoporosis

Densitometric studies gain even wider acceptance in the monitoring, treatment and diagnosis of metabolic bone diseases. The paper includes a number of views on the ways of using densitometric equipment in screening for osteoporosis, and remarks on the interpretation of the obtained results.     

Structural group classification technique based on regional fMRI BOLD responses

This paper presents a new multigroup classification method based on subtle differences in regional brain activity during the completion of a functional magnetic resonance imaging (fMRI) challenge paradigm. Classification is performed based on features derived from BOLD time intensity curves in selected regions of interest (ROI). For each ROI, a mean time intensity curve [called mean regional response (MRR)] is calculated from realigned and normalized datasets. The overall subject performance is characterized with a vector of features obtained using nonlinear modeling of all subject's MRRs with a mixture of time shifted Gaussian functions. The classification is performed in the reduced-dimension optimal discrimination space, obtained through canonical transformations of original feature space. In order to demonstrate feasibility of the proposed method, classification of three groups of subjects is presented. The three groups are defined as heavy marijuana smokers after 24 hours of abstinence, heavy marijuana smokers after 28 days of abstinence, and healthy nonusing controls. The proposed method can be useful as an analytic tool for the discrimination of different groups of subjects based on temporal features of functional magnetic resonance imaging activation.     

Influence of bioflavonoids from the radix extract of Scutellaria baicalensis on the level of serum lipids, and the development of laboratory rats fed with fresh and oxidized fats

The aim of this study was to assess the influence of bioflavonoids from the radix of Scurellaria baicalensis on the level of lipids, via the determination of the concentrations of triglycerides, total cholesterol and high-density lipoprotein (HDL) cholesterol in the plasma of laboratory rats fed high-fat and high-cholesterol diets, and via the calculation of their atherogenic index. We also studied the influence of bioflavonoids on their physical development by measuring the increase in their body mass and liver mass. The rats were fed a diet with a 15% content of fresh or oxidized lard or sunflower oil, along with 0.5% added cholesterol. 0.05% S. baicalensis radix extract was added to the diet of half of the rats as the source of bioflavonoids. In the group of rats fed a diet containing oxidized oil we observed a significantly lower increase in body mass (15.5 +/- 7.6 g/4 weeks/rat) than that observed for the control rats (77.0 +/- 15.7 g/4 weeks/rat). The addition of S. baicalensis radix extract to the diet raised the increase in body mass in the groups receiving oil as the source of fat; those receiving fresh oil had a 40% increase, and those receiving oxidized oil showed a 300% increase relative to the appropriate controls. In all the groups of rats fed a diet with bioflavonoids added, a beneficial decrease in the plasma triglyceride content was observed relative to the appropriate controls. In the plasma of rats on a diet containing the extract and fresh or oxidized oil or fresh lard, we observed a beneficial reduction in the total cholesterol level relative to the appropriate controls. The atherogenic index was higher for the group of animals fed with fresh lard than for those fed with fresh oil, and higher for those fed with oxidized oil than for those fed with oxidized lard. The addition of bioflavonoids to the diet beneficially reduced the atherogenic index value in the group fed with fresh oil, and increased its value in the group fed with oxidized lard.     

Exercise-Induced Plasticity in Signaling Pathways Involved in Motor Recovery after Spinal Cord Injury

Spinal cord injury (SCI) leads to numerous chronic and debilitating functional deficits that greatly affect quality of life. While many pharmacological interventions have been explored, the current unsurpassed therapy for most SCI sequalae is exercise. Exercise has an expansive influence on peripheral health and function, and by activating the relevant neural pathways, exercise also ameliorates numerous disorders of the central nervous system (CNS). While the exact mechanisms by which this occurs are still being delineated, major strides have been made in the past decade to understand the molecular underpinnings of this essential treatment. Exercise rapidly and prominently affects dendritic sprouting, synaptic connections, neurotransmitter production and regulation, and ionic homeostasis, with recent literature implicating an exercise-induced increase in neurotrophins as the cornerstone that binds many of these effects together. The field encompasses vast complexity, and as the data accumulate, disentangling these molecular pathways and how they interact will facilitate the optimization of intervention strategies and improve quality of life for individuals affected by SCI. This review describes the known molecular effects of exercise and how they alter the CNS to pacify the injury environment, increase neuronal survival and regeneration, restore normal neural excitability, create new functional circuits, and ultimately improve motor function following SCI.     

An X-ray structural analysis of cesium substitution in the barium hollandite phase of synroc

The X-ray structures of polycrystalline barium hollandite with cesium partially substituting for barium (viz [Ba_xCs_y] [Al_2x+yTi_{8 ? 2x ? y}]O₁₆) have been determined using the Rietveld refinement technique. Electron microprobe results indicate that the level of cesium substitution is constrained by the condition that the total volume occupied per unit cell by the cesium and barium ions remains substantially constant. X-ray refinement revealed that the structural parameters defining the positions of the titanium, aluminium and oxygen ions are not affected greatly by cesium substitution. The only significant change occurs in the parameter z which defines the average Cs/Ba position. This increases with the level of cesium indicating that these ions tend to occupy a more central location with respect to their coordinating oxygen ions. An analysis of the (Cs/Ba)-O bond lengths suggests a limit of structural stability corresponding to 0.25 cesium ions per unit cell.     

Modification of polyamide fibers (PA6) by grafting polyacrylamide (PAM)

The grafting of polyacrylamide (PAM) onto PA6 knitted fabric in aqueous systems under the atmosphere of nitrogen or air was examined. The grafting process was initiated by oxidation with air oxygen, forming hydroperoxide groups. Effects of time and temperature of oxidation and of the grafting conditions, such as concentration of monomer, temperature, and time, on the rate and degree of grafting were determined. The optimum grafting conditions, ensuring the minimum amount of homopolymer, were found (oxidation temperature 413 K, oxidation time 10 min, grafting temperature under nitrogen 353–373 K, grafting time 1 h, monomer concentration 0.7 mol/dm³). The activation energy of the grafting under nitrogen and air at 313–373 K was found to be 25.74 and 42.25 kJ/mol, respectively. The hydroscopicity, capillarity, disperse dye absorption, and electrical resistance of the modified PA-6 fabrics were determined. Some improvement of these properties was observed, depending on the degree of PAM grafting and the type of posttreatment with hydrazine and 3-bromopropionic acid. © 1995 John Wiley & Sons, Inc.     

Statistical evaluation of different technological and rheological tests of Polish wheat varieties for bread volume prediction

Forty‐two Polish wheat flour were used to establish correlation coefficients between protein content, Zeleny test, falling number value, amylograph viscosity, farinograph water absorption, bread volume and rheological properties of dough, as shown by use of a extrusion chamber and alveograph. The equations expressing the changes of bread volume and flour water absorption as a function of significantly correlated parameters were calculated. The correlations and their significance depended on wheat quality and the alveographic parameters were significantly correlated with the dough extrusion parameters. The dough extrusion parameters were significantly correlated only with the water absorption of soft wheats. The dough rheological tests were correlated to a greater extent with the values of the Zeleny test than to the protein content. The prediction of the bread volume as a function of flour quality parameters and dough rheological properties was best done by grouping wheat varieties into specific qualitative classes.     

Zum Tragverhalten von Verbunddübeln – Teil 1: Tragverhalten unter statischer Belastung

Verbunddübel stellen eine sehr tragfähige und robuste Verbindung auch bei hochfesten Betonen zwischen Stahlbauteilen und Betonquerschnitten dar. Die Herstellung des Stahldübels ist dabei einfach und wirtschaftlich. Mittels Verbunddübelleisten lassen sich neue Querschnitte für den konstruktiven Ingenieurbau entwickeln. Halbierte Walzprofile, die mit der speziellen Geometrie der Verbunddübel geschnitten wurden, werden als außenliegende Bewehrung im Verbundbau eingesetzt. In zwei Teilaufsätzen wird die Bemessung der Verbunddübel für unterschiedliche Randbedingungen und Belastungsarten erläutert. Der erste Beitrag befasst sich mit der Technologie der Verbunddübel, deren Tragverhalten und der Bemessung der Verbindung unter ruhender Belastung. Das Ermüdungsverhalten ist Schwerpunkt in einem zweiten Aufsatz. Die Problemstellung wird ausführlich erläutert und ein Bemessungsvorschlag auf Grundlage des Strukturspannungskonzeptes vorgestellt. Load bearing behaviour of composite dowels – Static loads (part I). Composite dowels realise a high load bearing capacity for connections between concrete and steel. The technology establishes a short time and cost‐effective production process. Using composite dowels for shear transmission new and innovative cross‐sections can be designed. Halved rolled sections which have been cut along with a specific dowel geometry are applied as external reinforcement. The publication is divided into two parts describing design of composite dowels for different boundary conditions and load cases. Foremost the technology, their load bearing behaviour, the design concepts for composite dowels for static loads are highlighted. The behaviour under cyclic load, will be introduced in a second part. The fatigue behaviour will be explained in detail and design concepts based upon the hot spot stress will be given.     

The toxicity in vitro of titanium dioxide nanoparticles modified with noble metals on mammalian cells

The aim of the presented work was to evaluate the effect of modification of titanium dioxide nanoparticles with noble metals and their oxides on selected mammalian cells. The in vitro cytotoxicity studies of titanium dioxide (TiO₂) nanoparticles modified with Au, Ag, Pd, Ag₂O, and PdO with reference to the unmodified TiO₂ nanoparticles were presented. The evaluation of cytotoxic activity of the tested nanocomposite particles was carried out using three cell lines: Caco-2 colorectal epithelial adenocarcinoma cells, BJ normal human skin fibroblasts, and L929 mouse fibroblasts. The in vitro studies included determination of cell viability after 24 and 48 hours of exposure to the nanocomposite particles, using the MTT assay, as well as flow cytometry with Annexin V-FITC staining. Our results indicate that irrespectively of the kind of cell line and assay used, nanoparticles of unmodified titanium dioxide as well as those with addition of gold and palladium have a slight impact on cell viability at the investigated concentration range (10-200 μg/mL). Nanoparticles with addition of silver (Ag and Ag₂O), were found to have significantly higher toxic effect, the level of which varied depending on the cell line and assay used.