Spectroscopic studies of MFI and USY zeolite layers over stainless steel 316L wire gauze meshes.

The objective of our study was to develop and optimize the in situ synthesis of zeolitic thin coatings with USY (ultrastabilised form of faujasite) and MFI (Model Five) type structure on metallic structured catalysts supports using the hydrothermal method. Thus, obtained zeolitic materials were studied in terms of their prospective activity in selective catalytic reduction of nitrogen oxides (SCR of NOx) with ammonia. Optimization of the preparation method consisted of several steps including: the pretreatment of steel carrier to obtain an adhesive surface, hydrothermal synthesis of zeolites at different conditions and adjustment of the zeolite structure type (MFI vs. USY). As a result, uniform zeolitic layers were deposited on steel supports. Prepared structured supports were ion-exchanged with copper or cobalt precursors to obtain active catalysts and then characterised by various physicochemical methods with a particular reference to the in situ Fourier-Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible Diffusion Reflectance Spectroscopy (DRS-UV/VIS) and Raman spectroscopy. For CuUSY sample, slightly better catalytic properties are related to higher copper content. In the case of Co-samples, worse catalytic properties in comparison with Cu counterparts might imply from higher concentration of Brønsted acid sites, lower cobalt loading (thus concentration of Lewis acid sites) and the presence of cobalt cation significantly in oxide form (evidenced by Raman, DRS-UV/VIS spectroscopy and by in situ FT-IR sorption studies).

Structural and optical study on antimony-silicate glasses doped with thulium ions.

Structural, spectroscopic and thermal properties of SiO2-Al2O3-Sb2O3-Na2O glass system doped with 0.2 mol% Tm2O3 have been presented. Synthesis of antimony-silicate glasses with relatively low phonon energy (600 cm(-1), which implicates a small non-radiative decay rate) was performed by conventional high-temperature melt-quenching methods. The effect of SiO2/Sb2O3 ratio in fabricated Tm(3+) doped glass on thermal, structural and luminescence properties was investigated. On the basis of structural investigations decomposition of absorption bands in the infrared FTIR region was performed, thus determining that antimony ions are the only glass-forming ions, setting up the lattice of fabricated glasses. Luminescence band at the wavelength of 1.8 µm corresponding to (3)F4→(3)H6 transition in thulium ions was obtained under 795 nm laser pumping. It was observed that combination of relatively low phonon energy and greater separation of optically active centers in the fabricated glasses influenced in decreasing the luminescence intensity at 1800 nm.

The effects and use of maintenance newsletters in a smoking cessation intervention.

This article evaluates the effects and use of adjuncts to a televised smoking cessation program, based on the American Lung Association's "Freedom From Smoking in 20 Days." Subjects were randomized to maintenance and control conditions. The maintenance condition received newsletters with information and support addressing different stages in the cessation process and information about a telephone hotline. The maintenance condition did not increase cessation at any wave of interviewing, assessed by multiple point or point prevalence of abstinence. Those abstinent at 6 months and those who had made an attempt to stop smoking by that time were more likely to have used the newsletters and were more likely to have used the sections relevant to their cessation stage. Rates of use of the telephone hotline were low. The newsletters appear to be useful to smokers who are predisposed to use written materials.

Heart rate changes in partially restrained rats during behaviorally and pharmacologically evoked emotional states.

The effect of fear and relief from fear on heart rate (HR) was studied in partially restrained adult male rats. The emotional state was influenced behaviorally with the use of Pavlovian aversive conditioning procedure, and pharmacologically by injections of the selected anxiolytics and anxiogenics. A signal of danger (DS)--light or tone, preceded tail-shock (excitatory trials), while a signal of safety (SS), respectively tone or light, overlapped last 3s of 5s DS and predicted an omission of this expected aversive event (inhibitory trials). To assess the stability of HR changes to DS and SS we analyzed whether and how the experimental conditions (modality and position of signals, the ratio of numbers of excitatory to inhibitory trials in the session) influenced HR. HR changes to DS were different in pattern, stability and direction when compared to HR changes in response to SS. Reactions to DS, although accompanied mainly by conditioned bradycardia, were not consistent and depended on experimental conditions. However, the SS always evoked conditioned tachycardia. Anxiolitycs--benzodiazepines (diazepam and midazolam) and buspirone--influenced HR in nonconsistent manner. Anxiogenics--PTZ and FG7142 were without significant effects on HR. HR could not be trusted therefore as direct index of pharmacologically induced emotional states. The results are discussed in the context of possible biobehavioral meaning of HR changes in response to danger and safety and their reliability as fear/relief correlates.

The alimentary and social instrumental performance in dogs is suppressed by various doses of amphetamine.

Amphetamine was administrated intramuscularly 20-25 min before each experimental session in doses of: 0.2 mg/kg, 0.5 mg/kg and 1.0 mg/kg. Each dose was applied twice and preceded by a regular experimental sessions without any treatment. An instrumental performance consisted of alimentary-social differentiation of two tones reinforced either by food or by sensory-social reward (petting by the experimenter). Amphetamine produced dose dependent decrease of the instrumental performance of both alimentary and social responses. This decrease was however not equal regarding both reactions. The dose of 1 mg/kg produced deep, statistically significant deterioration of alimentary as well as social responses. After the administration of the dose of 0.5 mg/kg the decrease of alimentary responses was equal to that produced by 1 mg/kg, whereas social responses were less deteriorated. After the dose of 0.2 mg/kg the reduction of alimentary responses was smaller than produced by 0.5 mg/kg but still more pronounced than in the case of socially reinforced reactions. The results confirm our previous data that amphetamine suppresses positively motivated instrumental performance in dogs. The results also show that amphetamine-evoked suppression is dose dependent and that it is different for alimentary and social responses. This might indicate that the positive reward system is not homogenous but consists of some subsystems related to different kinds of reward. It is concluded that the suppressing effect of amphetamine is due to the inhibitory effect on motivation, but not on purely instrumental mechanisms nor on hedonic processes.

Estimation of the distribution of the EMG signal amplitude.

Quantitative analysis of electromyographic (EMG) data still demands new methods. One of the methods is based on counting occurrences of signal crossings of "noise level" (per time unit). This provides an estimator of the so called "aggregate activity." These data can be obtained by a spike trigger connected to a computer. Comparison of total activity of firing motor units in intact and affected muscles may give important information about the neuromuscular system in norm and pathology. The aggregate activity method does not seem, however, to be completely objective, because its results depend on the value of noise level selected by the experimenter. Thus, we propose a modification that allows: (1) quantitative estimation of how the results obtained with the aggregate activity method depend on the value of selected level, and (2) assessment of the distribution of the EMG signal amplitude--i.e., appearance of particular height spikes in the signal. The advantages and disadvantages of the method are discussed in the context of two experimental models.

Apparatus for studying behavior and learning in restrained rats.

A new treadmill/stand apparatus for a rat is described. It will be useful in behavioral experiments when control of the animal's position in the training chamber is required while considerable freedom of movement, including locomotion, is desired. The position and distance relative to sources of stimuli are thus kept constant. The speed and the distance of ambulation are easily monitored. The rats are sufficiently restrained to enable easy recording of various measures such as EKG, EMG or EEG, etc. Classical and instrumental conditioning procedures are easily implemented. An example of the data from acquisition training during Pavlovian conditioning is shown (diaphragm EMG, heart rate (HR), locomotion and vocalization).

Moganite in selected Polish chert samples: the evidence from MIR, Raman and X-ray studies.

The authors discuss the results of structural investigations (XRD, MIR, Raman) of Polish cherts from different geological formations. The X-ray diffraction analyses explicitly confirmed the presence of moganite, which was identified on the basis of satellite XRD peaks positioned/occurring close to the quartz reflections and the additional reflections with the dhkl values 4.456 and 3.101 Ǻ, and established its amounts as varying between about 1 and above 17 wt%. The mid-infrared and Raman spectroscopy also proved the presence of moganite, indicated by the 695 and 560-555 cm(-)(1) bands, respectively. These analytical finds allow to identify moganite in samples containing various SiO2 polymorphs.

Preparation and structural studies of black glasses based on ladder-like silsesquioxanes.

Black glasses are very interesting and promising materials from the point of their thermal and mechanical resistance. They can be used as protective layers on different kind of substrates, like steel, titanium, glasses. Controlling amount of carbon introduced to its structure is crucial for the properties of the material. Samples were prepared by sol-gel method using ladder-like silsesquioxanes as precursor and were heat-treated at 800°C in inert atmosphere. Middle infrared, EDX and MAS NMR studies were carried out on heated samples to determine their structure. All methods confirmed presence of Si-C bonds in the resulting material. Theoretical MIR spectrum, of the constructed black glass model, allowed to make a precise assignment of bands in the experimental spectrum.

Spectroscopic studies of electrophoretically deposited hybrid HAp/CNT coatings on titanium.

Carbon nanotubes deposited on the surface of the metal can be used in a wide variety of applications for modern medicine including: sensors and sensor array devices, electrodes for neural system stimulation, scaffolds for improved healing process for bone defects. Additionally it is debated if deposited on the surface of e.g. endoprosthesis, CNT coating can significantly increase the strength of the tissue/bone joint and stimulate a fast integration of the implant and the tissue. The aim of this paper is the analysis of the electrophoretically deposited nanocomposite coating made of hydroxyapatite nanoparticles and carbon nanotubes on the surface of titanium. The paper concentrates on the analysis of the layer's structure and its bioactivity properties. The nanocomposite films were investigated using Raman Spectroscopy as well as AFM and SEM microscopy. The measurements were conducted at every stage of layer preparation and after bioactivity test. Bioactivity was evaluated by in vitro test in Simulated Body Fluid (SBF, 37°C, for 30days). It was shown that hybrid HAp/CNT layers are very attractive materials for modification of the surface of metallic orthopedic implants.

Fabrication and characterization of oxygen - diffused titanium using spectroscopy method.

A thin native oxide film that forms on the titanium surface makes contact with the bone tissue has been considered to be of great importance to successful osseointegration. The study investigated oxygen-diffused grade 2 titanium obtained by introducing oxygen into the titanium crystal lattice using thermal treatment in fluidized bed performed at 610°C and 640°C in 6, 8, 12h. The thermal treatment at different temperatures and different times led to the formation of a TiO2 rutile film on the titanium surface and a concentration gradient of oxygen into titanium (XRD/GID analyses and GDOS results). Moreover Raman spectroscopy results showed that the TiO2 film on the surface titanium was composed of two oxides (TiO2), i.e. anatase and rutile, for the analyzed variants of heat treatment. The aim of the present study was to establish the optimum conditions for obtaining oxygen-diffused TiO2 film. The results obtained in the study demonstrated that the use of a fluidized bed for titanium oxidation processes allows for obtaining uniform oxide layers with good adhesion to the substrate, thus improving the titanium surface to suit biomedical applications.

Studying functional properties of hydrogel and silicone-hydrogel contact lenses with PALS, MIR and Raman spectroscopy.

Determination of free volume holes of the hydrogel and silicone-hydrogel polymer contact lenses were investigated. Two types of polymer contact lenses were used as materials: the first is a hydrogel contact lenses Proclear family (Omafilcon A), while the second is a silicone-hydrogel contact lens of the family Biofinity (Comfilcon A). Positron annihilation lifetime spectroscopy PALS was used to characterize geometrical sizes and fraction of the free volume holes in the investigated samples. There is a clear difference in the free volume sizes and their fractions between silicone-hydrogel and polymer hydrogel contact lenses which in turn are connected with oxygen permeability in these lenses. Apart from that, spectroscopic (middle infrared) MIR and Raman examinations were carried out in order to demonstrate the differences of the water content in the test contact lenses.

Analysis of thermal and structural properties of germanate glasses co-doped with Yb(3+)/Tb(3+) ions.

In the work the new glass compositions in the GeO2-GaO-BaO system have been prepared and thermal, structural properties of in germanate glasses co-doped with Yb(3+)/Tb(3+)ions were studied. Glasses were obtained by conventional high-temperature melt-quenching technique. The study of the crystallization kinetics processes of glasses co-doped with 0.7Yb2O3:0.7Tb2O3 was performed with DSC measurements. The activation energies have been calculated using Freedman analysis and verified with the Flynn-Wall-Ozawa method. In this order, the DSC curves have been registered with different heating rates, between 5 and 15 degrees/min. The structure of fabricated glasses has been studied by infrared and Raman spectroscopes. The effect of heat treatment on the structural properties was determined. In all glass samples the dominated infrared absorbance band at 800cm(-1) corresponds to asymmetric stretching motions of GeO4 tetrahedra containing bridging (Ge-O(Ge)) and non-bridging (Ge-O(-)) oxygens. Additionally, the influence of heat treatment on the luminescent properties was evaluated. Strong luminescence at 489, 543, 586 and 621nm corresponding to (5)D4→(7)FJ (J=6, 5, 4, 3) transitions was measured. The highest upconversion emission intensity was obtained in the germanate glass co-doped with 0.7Yb2O3/0.7Tb2O3.

Voids in mixed-cation silicate glasses: Studies by positron annihilation lifetime and Fourier transform infrared spectroscopies.

PALS in comparison with FTIR studies have been applied to investigate the structure of different oxide glasses. Three components of the positron lifetime τ (τ1 para- and τ3 ortho-positronium and τ2 intermediate lifetime component) and their intensities were obtained. The results of the calculation of mean values of positron lifetimes for the investigated glasses showed the existence of a long-living component on the positron annihilation lifetime spectra. From the Tao-Eldrup formula we can estimate the size of free volume. On the basis of the measurements we can conclude that the size and fraction of free volume reaches the biggest value for the fused silica glass. The degree of network polymerisation increases void size.

SiOC glasses produced from silsesquioxanes by the aerosol-assisted vapor synthesis method.

In this paper, we describe a new method based on aerosol-assisted vapor synthesis for making glass materials by pyrolysis of readily available silsesquioxanes CH3Si(OCH3)3 and CH3Si(OC2H5)3. Combined powder X-ray diffraction (XRD) and spectroscopic studies in the far infrared region (FIR) showed that under applied conditions the method yielded amorphous materials. Subsequent structural studies with the application of the (29)Si and (13)C MAS NMR, Raman, and middle infrared (MIR) techniques led to the conclusion that the pyrolysis of the silsesquioxane precursors resulted in glass materials with a structure of amorphous silica v-SiO2. In the case of certain glasses prepared from CH3Si(OCH3)3, they were also shown to possess in the structure some Si-C bonds (black glasses), whereas those originated from CH3Si(OC2H5)3 were composites that in addition to the silica glass phase contained domains of free/unbound carbon.

Experience with Direct and Indirect UHT Processing of Milk - A Canadian Viewpoint.

This brief overview includes some of the Canadian industrial experience gained recently with UHT processing of milk and other dairy products. Emphasis is placed on the differences between direct and indirect heating systems in terms of process engineering, product quality, consumer acceptance, public health aspects and economy. Documented advantages include less fouling, better heat transfer and less heat damage to the final product for direct systems, and less elaborate requirements for ancillary equipment and lower costs for indirect technology. Market performance data from some of the four industrial Canadian producers of 2% and chocolate milk indicate better than expected consumer acceptance due to product quality and other market-related aspects of the UHT process.

Lactose absorption by postweaning rats from yogurt, quarg, and quarg whey.

Lactose-intolerant postweaning rats were fed experimental diets including yogurt, quargs prepared from yogurt culture and buttermilk culture, and two types of whey obtained from quarg processing. After feeding each diet for a period of 7 d, absence of blood glucose elevation and occurrence of diarrhea were used as indicators of lactose malabsorption. Blood glucose assays and absence of diarrhea indicated that yogurt and quargs prepared from yogurt and buttermilk culture were well tolerated by the rats. Wheys containing the same levels of viable organisms and lactose as the quargs caused severe symptoms of diarrhea and poor lactose absorption as indicated by no changes in blood glucose levels. Plate counts and enzyme assays of gastrointestinal contents confirmed presence of viable culture organisms and beta-galactosidase activity after feeding the two types of quarg. The availability of viable organisms, the exogenous lactase activity, and especially the slow gastric emptying may all have contributed to more efficient hydrolysis and digestion of lactose from quargs and yogurt than from the wheys.

Whole blood and mononuclear cell glutathione response to dietary whey protein supplementation in sedentary and trained male human subjects.

Sedentary male subjects (n=9) on a controlled diet were fed two doses (0.8 or 1.6 g/kg body mass) of a whey protein isolate (WPI), in addition to an isocaloric placebo; blood samples were drawn over a 4-h period and glutathione concentration determined. There was no effect of the supplementation at either level over the 4-h sampling period. The effects of a WPI supplemented diet on glutathione concentrations in whole blood as well as peripheral mononuclear cell populations were also investigated over a 6-week period in male subjects (n=18) involved in arduous aerobic training; blood was collected prior to and following a 40 km simulated cycling trial. The aerobic training period resulted in significantly lower glutathione concentrations in whole blood, an effect that was mitigated by WPI supplementation. A significant increase in mononuclear cell glutathione was also observed in subjects receiving the WPI supplement following the 40 km simulated cycling trial.

Formation of Lysino-Alanine in Alkaline Extracts of Chicken Protein.

Bone residues from mechanical deboning of chicken backs, necks and spent layers were extracted at pH 9.2, 10.0, 10.7 and 11.5. The centrifuged liquid protein extracts were kept at 22, 35 and 50°C for 1, 4 and 16 h. Determinations of lysino-alanine (LAL) were made after freeze-drying and fat extraction of the treated samples. No LAL was detected in any samples treated for 1 h. Samples treated for 4 h showed measurable amounts of LAL only at pH 11.5 at all three temperatures used, and at pH 10.7 at 50°C. After 16 h, LAL was produced at all pH treatments at 50°C; small amounts were also formed at 22 and 35°C at pH 10.7 and 11.5. It is concluded that the proposed alkali extraction procedure would not produce LAL in the protein extract under technologically optimal conditions.