Comparative sorption and desorption of benzo[a]pyrene and 3,4,3',4'-tetrachlorobiphenyl in natural lake water containing dissolved organic matter

The sorption and desorption of two model compounds, benzo[a]pyrene (BaP) and 3,4,3',4'-tetrachlorobiphenyl (TCBP), were studied in natural lake water with high dissolved organic matter (DOM) content using the equilibrium dialysis and Tenax extraction methods. The sorption of TCBP was lower and reached steady value more slowly than did BaP. Tenax extraction revealed at least two differently desorbing fractions for both model compounds, which also supported the conclusion that DOM-HOC associations may involve several mechanisms. The rapidly desorbing fraction may be attributed to freely dissolved and loosely sorbed compound, whereas the more strongly sorbed fraction may indicate the presence of specific binding sites. The data indicated that the association between hydrophobic organic contaminants (HOC) and DOM is not simply absorption that is solely driven by the lipophilicity of the sorbates. Although contact time had a rather negligible effect on the sorption of BaP, the proportion of desorption resistant fraction increased with time, whereas the desorption of TCBP was less affected by contact time. Steric factors may be the cause of the lower sorption and smaller desorption resistant fraction of TCBP. The results indicate potential differences in the behavior of PAHs and PCBs in the aquatic environment.     

Nanocrystalline WC-Co HVAF Coatings by Utilizing Novel Powder Manufacturing Route Using Water-Soluble Raw Materials

In this study, nanostructured WC-Co coatings were produced using experimental nanocrystalline WC-12Co and WC-24Co powders produced by a novel chemical synthesis route. Test coatings were produced using HVAF spraying keeping the temperature as low as possible during the deposition in order to avoid decomposition of the nanocarbides. In experimental powders, two different Co incorporation methods were used: a conventional way in which cobalt was incorporated as a metallic Co powder and a chemical synthesis way in which cobalt acetate was used as a cobalt source. When using cobalt acetate, it decomposes to metallic cobalt during the process. Experimental powders in which cobalt acetate has been used as cobalt source resulted poor deposition efficiency. With warmer parameters, powders resulted better DE, but significant WC decarburization and the dissolution into the matrix phase occurred. Powders in which Co has been introduced as Co powder showed enhanced DE enabling spraying with decreased temperature and higher particle velocity, resulting in coatings with less WC decomposition. Especially, an experimental powder in which Co has been incorporated both as Co powder and as Co-Ac results very fine nanocarbide structure with significantly less WC decomposition having a hardness value of 1201 HV0.3, even with 24% Co.     

WCDMA multicarrier receiver for base-station applications

The multicarrier receiver IC described in this paper receives four adjacent WCDMA channels simultaneously in order to reduce the component count of a base-station. The receiver uses low-IF architecture and it is fabricated with a 0.25-/spl mu/m SiGe BiCMOS process to meet the high-performance requirements set by the base-station application. The receiver includes a dual-input low-noise amplifier (LNA), quadrature mixers, a local-oscillator (LO) divider, IIP2 calibration circuits, 10-MHz low-pass filters, and ADC buffers. The receiver noise figures, measured over the downconverted WCDMA channels centered at 2.5-MHz and 7.5-MHz intermediate frequencies, are 3.0 dB and 2.6 dB, respectively. The receiver achieves 47-dB voltage gain and -12-dBm out-of-band IIP3 and consumes 535mW from a 2.5-V supply.     

On the Correlation of Effective Terahertz Refractive Index and Average Surface Roughness of Pharmaceutical Tablets

In this paper, we have studied terahertz (THz) pulse time delay of porous pharmaceutical microcrystalline compacts and also pharmaceutical tablets that contain indomethacin (painkiller) as an active pharmaceutical ingredient (API) and microcrystalline cellulose as the matrix of the tablet. The porosity of a pharmaceutical tablet is important because it affects the release of drug substance. In addition, surface roughness of the tablet has much importance regarding dissolution of the tablet and hence the rate of drug release. Here, we show, using a training set of tablets containing API and with a priori known tablet’s quality parameters, that the effective refractive index (obtained from THz time delay data) of such porous tablets correlates with the average surface roughness of a tablet. Hence, THz pulse time delay measurement in the transmission mode provides information on both porosity and the average surface roughness of a compact. This is demonstrated for two different sets of pharmaceutical tablets having different porosity and average surface roughness values.     

The effect of low-intensity pulsed ultrasound on bone healing in SR-PLLA rod fixed experimental distal femur osteotomy in rat

The effects of low-intensity pulsed ultrasound (30 mW/cm²) were investigated in experimental cancellous bone fracture healing in bioabsorbable self-reinforced poly-l-lactide (SR-PLLA) rod fixed distal femur osteotomy in rats. A transverse transcondylar osteotomy was fixed with one SR-PLLA rod in 32 male Wistar rats of the age of 20 weeks. Half of the rats had a daily 20-min ultrasound exposure for three weeks. The follow-up times were three, six, and 12 weeks. Radiographical, histological, microradiographical, oxytetracycline labeling, and histomorphometrical analyses were performed. No foreign-body reactions were noted. The biocompatibility of SR-PLLA and ultrasound was found to be good. In the radiological and histological assessments there was a slight tendency for enhanced healing in the ultrasound group at three weeks, but at six and 12 weeks no differences were observed. The histomorphometrical and oxytetracycline labeling analyses showed that ultrasound exposure had no significant effects on bone healing. The present study shows that there were no obvious findings to support the hypothesis that low-intensity pulsed ultrasound enhances bone healing in self-reinforced poly-l-lactide (SR-PLLA) rod fixed experimental metaphyseal distal femur osteotomy in rats. The observed good biocompatibility provides a safe starting-point for clinical trials on bioabsorbable fixation combined with low-intensity ultrasound.     

Development of Sesamol Carbamate-L-Phenylalanine Prodrug Targeting L-Type Amino Acid Transporter1 (LAT1) as a Potential Antiproliferative Agent against Melanoma

Sesamol is a compound reported to have anti-melanogenesis and anti-melanoma actions. Sesamol, however, has low intracellular drug concentration and fast excretion, which can limit its benefits in the clinic. To overcome this drawback and increase intracellular delivery of sesamol into the target melanoma, research has focused on L-type amino acid transporter 1 (LAT1)-mediated prodrug delivery into melanoma cells. The sesamol prodrug was designed by conjugating sesamol with L-phenylalanine at the para position with a carbamate bond. LAT1 targeting was evaluated vis-à-vis a competitive [¹⁴C]-leucine uptake inhibition. The sesamol prodrug has a higher [¹⁴C]-leucine uptake inhibition than sesamol in human LAT1-transfected HEK293 cells. Moreover, the sesamol prodrug was taken up by LAT1-mediated transport into SK-MEL-2 cells more effectively than sesamol. The sesamol prodrug underwent complete hydrolysis, releasing the active sesamol at 72 h, which significantly exerted its cytotoxicity (IC₅₀ of 29.3 µM) against SK-MEL-cells more than sesamol alone. Taken together, the strategy for LAT1-mediated prodrug delivery has utility for the selective uptake of sesamol, thereby increasing its intracellular concentration and antiproliferation activity, targeting melanoma SK-MEL-2 cells that overexpress the LAT1 protein. The sesamol prodrug thus warrants further evaluation in an in vivo model.     

Room‐Temperature Micropillar Growth of Lithium–Titanate–Carbon Composite Structures by Self‐Biased Direct Current Magnetron Sputtering for Lithium Ion Microbatteries

Here, an unidentified type of micropillar growth is described at room temperature during conventional direct‐current magnetron sputtering (DC‐MS) deposition from a Li₄Ti₅O₁₂+graphite sputter target under negative substrate bias and high operating pressure. These fabricated carbon–Li₂O–TiO₂ microstructures consisting of various Li₄Ti₅O₁₂/Li₂TiO₃/Li_x TiO₂ crystalline phases are demonstrated as an anode material in Li‐ion microbatteries. The described micropillar fabrication method is a low‐cost, substrate independent, single‐step, room‐temperature vacuum process utilizing a mature industrial complementary metal–oxide–semiconductor (CMOS)‐compatible technology. Furthermore, tentative consideration is given to the effects of selected deposition parameters and the growth process, as based on extensive physical and chemical characterization. Additional studies are, however, required to understand the exact processes and interactions that form the micropillars. If this facile method is further extended to other similar metal oxide–carbon systems, it could offer alternative low‐cost fabrication routes for microporous high‐surface area materials in electrochemistry and microelectronics.     

(Interactive) cinema as a model of mind

(Interactive) cinema is introduced as a model system for describing mind, inspired by Antonio Damasio’s approach (1999, 2002) to emotions and the conscious self. Damasio harnesses ‘movie’ as a metaphor for the integrated, unified composite of sensory images—visual, auditory, tactile, olfactory; the multimedia-show he calls mind. Assuming emotion to be the foundation of any cognitive act, cinema is discussed as a metaphoric externalisation of embodied mind. This discussion creates a novel dialogue between the contemporary philosophy of embodied mind by George Lakoff and Mark Johnson (1999), and the practice-based cinematic thinking of Russian film director Sergei Eisenstein (from the first half of the 20th century). The work Eisenstein did in order to construct an organic unity of cinematic form serves as the point of departure for an attempt to model the (interactive) film research project Obsession.     

Characterization of High-Velocity Single Particle Impacts on Plasma-Sprayed Ceramic Coatings

High-velocity impact wear can have a significant effect on the lifetime of thermally sprayed coatings in multiple applications, e.g., in the process and paper industries. Plasma-sprayed oxide coatings, such as Cr₂O₃- and TiO₂-based coatings, are often used in these industries in wear and corrosion applications. An experimental impact study was performed on thermally sprayed ceramic coatings using the High-Velocity Particle Impactor (HVPI) at oblique angles to investigate the damage, failure, and deformation of the coated structures. The impact site was characterized by profilometry, optical microscopy, and scanning electron microscopy (SEM). Furthermore, the connection between the microstructural details and impact behavior was studied in order to reveal the damage and failure characteristics at a more comprehensive level. Differences in the fracture behavior were found between the thermally sprayed Cr₂O₃ and TiO₂ coatings, and a concept of critical impact energy is presented here. The superior cohesion of the TiO₂ coating inhibited interlamellar cracking while the Cr₂O₃ coating suffered greater damage at high impact energies. The HVPI experiment has proven to be able to produce valuable information about the deformation behavior of coatings under high strain rates and could be utilized further in the development of wear-resistant coatings.     

Solid Lubrication on Hard Metal Specimens with Micropits Under Normal and Elevated Temperatures

Tribology Letters - We study the lubricated sliding of a rigid cylinder on a viscoelastic half space with a single characteristic retardation time. Besides the generalized inverse Hersey number...