Fourier Transform Infrared Microspectroscopy Combined with Principal Component Analysis and Artificial Neural Networks for the Study of the Effect of β-Hydroxy-β-Methylbutyrate (HMB) Supplementation on Articular Cartilage

The potential of Fourier Transform infrared microspectroscopy (FTIR microspectroscopy) and multivariate analyses were applied for the classification of the frequency ranges responsible for the distribution changes of the main components of articular cartilage (AC) that occur during dietary β-hydroxy-β-methyl butyrate (HMB) supplementation. The FTIR imaging analysis of histological AC sections originating from 35-day old male piglets showed the change in the collagen and proteoglycan contents of the HMB-supplemented group compared to the control. The relative amount of collagen content in the superficial zone increased by more than 23% and in the middle zone by about 17%, while no changes in the deep zone were observed compared to the control group. Considering proteoglycans content, a significant increase was registered in the middle and deep zones, respectively; 62% and 52% compared to the control. AFM nanoindentation measurements collected from animals administered with HMB displayed an increase in AC tissue stiffness by detecting a higher value of Young’s modulus in all investigated AC zones. We demonstrated that principal component analysis and artificial neural networks could be trained with spectral information to distinguish AC histological sections and the group under study accurately. This work may support the use and effectiveness of FTIR imaging combined with multivariate analyses as a quantitative alternative to traditional collagenous tissue-related histology.     

Removal of organic matter from water by PAC/UF system

The laboratory-scale ultrafiltration (UF) experiments were conducted to determine the effect of the presence of powdered activated carbon (PAC) on the UF process performance, in terms of flux decline and the possibilities of membranes cleaning during backwashing. Poly(vinylidene fluoride) membranes formed by the phase inversion technique were used in the UF experiments. A model solution was prepared as a mixture of humic acids (HA) and phenol in concentration of 10 and 1 mg l(-1), respectively. Commercial powdered activated carbons CWZ 11 and CWZ 30 (Gryfskand Sp. z o. o., Hajnówka, Poland) were used as the adsorbents. PAC dosage was in the range of 10-100 mg PAC l(-1). The process was carried out in the cross-flow system. It was found that PAC addition to the distilled water leads to a small drop in the permeate flux, regardless of PAC dose and its type. Although PAC particles are too large to block the membrane pores inside, they deposit on the membrane surface and partially can plug the surface pores. The experimental results demonstrate that the backwashing process applied in combined PAC/UF system was especially effective when PAC dosages were <20mg PAC l(-1). However, a similar permeate flux was maintained for all carbon dosages used and reached the value of about 1 m3 m(-2) d(-1). Moreover, no further drop in the permeate flux for PAC addition to the solution containing foulants (HA) was observed. Effectiveness of the removal of HA and phenol from the model solutions was also investigated. In the PAC/UF system HA were removed in about 90%, whereas the complete removal of phenol was achieved for PAC dosage equal to 100 mg l(-1).     

The Potential of Al2O3–ZrO2-Based Composites,Formed via CSC Method,in Linear Infrastructure Applications Based on Their Mechanical,Thermal and Environmental performance

Metallurgical and Materials Transactions A - Ceramic-ceramic composites have been prepared using the centrifugal slip casting method (CSC). The method has so far been mainly utilized in making...     

Trabecular Bone Parameters,TIMP-2, MMP-8, MMP-13, VEGF Expression and Immunolocalization in Bone and Cartilage in Newborn Offspring Prenatally Exposed to Fumonisins

Fumonisins are protein serine/threonine phosphatase inhibitors and potent inhibitors of sphingosine N-acyltransferase (ceramide synthase) disrupting de novo sphingolipid biosynthesis. The experiment was conducted to evaluate the effects of fumonisins (FB) exposure from the 7th day of pregnancy to parturition on offspring bone development. The rats were randomly allocated to either a control group (n = 6), not treated with FBs, or to one of the two groups intoxicated with FBs (either at 60 mg FB/kg b.w. or at 90 mg FB/kg b.w. Numerous negative, offspring sex-dependent effects of maternal FB exposure were observed with regards to the histomorphometry of trabecular bone. These effects were due to FB-inducted alterations in bone metabolism, as indicated by changes in the expression of selected proteins involved in bone development: tissue inhibitor of metalloproteinases 2 (TIMP-2), matrix metalloproteinase 8 (MMP-8), matrix metalloproteinase 13 (MMP-13), and vascular endothelial growth factor (VEGF). The immunolocalization of MMPs and TIMP-2 was performed in trabecular and compact bone, as well as articular and growth plate cartilages. Based on the results, it can be concluded that the exposure of pregnant dams to FB negatively affected the expression of certain proteins responsible for bone matrix degradation in newborns prenatally exposed to FB in a dose- and sex-dependent manner.     

Color correction for tone mapping

Tone mapping algorithms offer sophisticated methods for mapping a real-world luminance range to the luminance range of the output medium but they often cause changes in color appearance. In this work we conduct a series of subjective appearance matching experiments to measure the change in image colorfulness after contrast compression and enhancement. The results indicate that the relation between contrast compression and the color saturation correction that matches color appearance is non-linear and smaller color correction is required for small change of contrast. We demonstrate that the relation cannot be fully explained by color appearance models. We propose color correction formulas that can be used with existing tone mapping algorithms. We extend existing global and local tone mapping operators and show that the proposed color correction formulas can preserve original image colors after tone scale manipulation.     

Comparison of Four Subjective Methods for Image Quality Assessment

To provide a convincing proof that a new method is better than the state of the art, computer graphics projects are often accompanied by user studies, in which a group of observers rank or rate results of several algorithms. Such user studies, known as subjective image quality assessment experiments, can be very time‐consuming and do not guarantee to produce conclusive results. This paper is intended to help design efficient and rigorous quality assessment experiments and emphasise the key aspects of the results analysis. To promote good standards of data analysis, we review the major methods for data analysis, such as establishing confidence intervals, statistical testing and retrospective power analysis. Two methods of visualising ranking results together with the meaningful information about the statistical and practical significance are explored. Finally, we compare four most prominent subjective quality assessment methods: single‐stimulus, double‐stimulus, forced‐choice pairwise comparison and similarity judgements. We conclude that the forced‐choice pairwise comparison method results in the smallest measurement variance and thus produces the most accurate results. This method is also the most time‐efficient, assuming a moderate number of compared conditions.     

Environmental footprint as a criterion in the ZTA composites forming process via centrifugal slip casting

The main goal of this study was to optimize the technological process of forming and sintering Zirconia Toughened Alumina (ZTA) composites in terms of reducing energy demand. Based on the results of Life Cycle Assessment carried out according to ISO 14044 and EN 15805 standards, the elimination of preliminary homogenization of ceramic suspension in the planetary mill, allowed to reduce energy consumption by over 25%. The method of forming ZTA materials by CSC method, allowed to obtain finished tube-shaped products, which did not require any mechanical treatment after sintering. Such an approach may be an alternative solution for production of ZTA pipes that can be used in transport of aggressive substances, even in extreme corrosive or temperatures conditions.     

Rigid poly(vinyl chloride) gelation in a Brabender measuring mixer. III. Transformation in the torque maximum

The processing and structural effects occurring in a poly(vinyl chloride) (PVC) compound processed in a plastograph, at the time at which the maximum value of the torque (point X on the torque curve) was reached, were studied. The unplasticized PVC compound was processed at various temperatures (150–200°C) with a kneader operating at rotors speeds of 5–40 min^?1. The changes in the temperature of the compound due to kneading and its influence on the progress of PVC gelation were analyzed. The gelation progress was studied with differential scanning calorimetry, rheological measurements, and scanning electron microscopy. The maximum value of the torque occurred within the temperature range (170–180°C) of the PVC compound, and it was independent of the adjusted temperature of the mixing chamber. The processing of the PVC compound in the kneader, with high mechanical charges and a comparatively low adjusted temperature (150–170°C), spontaneously generated an effect of self‐heating, resulting in an increasing temperature of the compound. Despite the surprisingly high degree of gelation (80–98%) of the PVC compound processed under these conditions (as determined by differential scanning calorimetry), the scanning electron microscopy observations indicated significant nonhomogeneity of the fracture surface. Consequently, the kneaded PVC compound at point X of the torque curve could be treated as a two‐phase system composed of a liquid, amorphous phase and elements of a grain structure. The transformation of both phases (particularly the quantitative and qualitative changes), which was significantly dependent on the PVC temperature and the shear rate applied by the rotors, determined the state of the melted compound at this point of the torque curve. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007