PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application

High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.     

Aberration-free superresolution imaging via binary speckle pattern encoding and processing

We present an approach that provides superresolution beyond the classical limit as well as image restoration in the presence of aberrations; in particular, the ability to obtain superresolution while extending the depth of field (DOF) simultaneously is tested experimentally. It is based on an approach, recently proposed, shown to increase the resolution significantly for in-focus images by speckle encoding and decoding. In our approach, an object multiplied by a fine binary speckle pattern may be located anywhere along an extended DOF region. Since the exact magnification is not known in the presence of defocus aberration, the acquired low-resolution image is electronically processed via a parallel-branch decoding scheme, where in each branch the image is multiplied by the same high-resolution synchronized time-varying binary speckle but with different magnification. Finally, a hard-decision algorithm chooses the branch that provides the highest-resolution output image, thus achieving insensitivity to aberrations as well as DOF variations. Simulation as well as experimental results are presented, exhibiting significant resolution improvement factors.     

A better approach to goodness: Reply to Wagemans (1999).

In P. A. van der Helm and E. L. J. Leeuwenberg (see record 1996-01780-002), the authors presented a representation model for the goodness, or detectability, of visual regularities such as mirror symmetry and repetition. J. Wagemans (see record 1999-03499-009) acknowledged that this holographic goodness model has considerable explanatory power, but he also argued that it is not good enough yet. He challenged van der Helm and Leeuwenberg to qualify some open ends of their representation model, in particular those concerning its process assumptions. He also questioned the authors' assessment of previous goodness accounts such as S. E. Palmer's (1982, 1983) transformational approach and his own bootstrap model. He concluded that it is expedient to aim at a synthesis of useful aspects of diverse accounts of goodness, but he did not establish such a synthesis. Van der Helm and Leeuwenberg agree with his conclusion that such a synthesis is a worthy cause, but they disagree with his evaluation of the issues involved. This article is a reply with an alternative evaluation of these issues, advancing the discussion to a process-representation synthesis called holographic bootstrapping. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tepotinib Inhibits Several Drug Efflux Transporters and Biotransformation Enzymes: The Role in Drug-Drug Interactions and Targeting Cytostatic Resistance In Vitro and Ex Vivo

Tepotinib is a novel tyrosine kinase inhibitor recently approved for the treatment of non-small cell lung cancer (NSCLC). In this study, we evaluated the tepotinib’s potential to perpetrate pharmacokinetic drug interactions and modulate multidrug resistance (MDR). Accumulation studies showed that tepotinib potently inhibits ABCB1 and ABCG2 efflux transporters, which was confirmed by molecular docking. In addition, tepotinib inhibited several recombinant cytochrome P450 (CYP) isoforms with varying potency. In subsequent drug combination experiments, tepotinib synergistically reversed daunorubicin and mitoxantrone resistance in cells with ABCB1 and ABCG2 overexpression, respectively. Remarkably, MDR-modulatory properties were confirmed in ex vivo explants derived from NSCLC patients. Furthermore, we demonstrated that anticancer effect of tepotinib is not influenced by the presence of ABC transporters associated with MDR, although monolayer transport assays designated it as ABCB1 substrate. Finally, tested drug was observed to have negligible effect on the expression of clinically relevant drug efflux transporters and CYP enzymes. In conclusion, our findings provide complex overview on the tepotinib’s drug interaction profile and suggest a promising novel therapeutic strategy for future clinical investigations.     

Zapotin,a Polymethoxyflavone,with Potential Therapeutic Attributes

The use of plants as traditional medicines is common and has prevailed in many different cultures over time. Polymethoxyflavones (PMFs) are natural polyphenols from the group of flavonoids. Zapotin, a member of the PMFs, is found mainly in citrus plants and is almost exclusively limited to their peels. The chemical structure of zapotin has been questioned from the very beginning, since the structure of flavonoids with a single oxygen atom in the C2′ position is extremely rare in the plant kingdom. To clarify this, the structural determination and bio-inspired synthesis of zapotin are discussed in detail in this review. Due to the broad biological potential of PMFs, the complication in the isolation process and characterization of PMFs, as well as their purification, have been estimated by adapting various chromatographic methods. According to available data from the literature, zapotin may be a promising curative agent with extensive biological activities, especially as a chemopreventive factor. Apart from that, zapotin acts as an antidepressant-like, anticancer, antifungal, and antioxidant agent. Finally, accessible studies about zapotin metabolism (absorption, distribution, metabolism, excretion, and toxicity) underline its potential in use as a therapeutic substance.     

Gene Expression Data Mining Reveals the Involvement of GPR55 and Its Endogenous Ligands in Immune Response,Cancer, and Differentiation

G protein-coupled receptor 55 (GPR55) is a recently deorphanized lipid- and peptide-sensing receptor. Its lipidic endogenous agonists belong to lysoglycerophospholipids, with lysophosphatidylinositol (LPI) being the most studied. Peptide agonists derive from fragmentation of pituitary adenylate cyclase-activating polypeptide (PACAP). Although GPR55 and its ligands were implicated in several physiological and pathological conditions, their biological function remains unclear. Thus, the aim of the study was to conduct a large-scale re-analysis of publicly available gene expression datasets to identify physiological and pathological conditions affecting the expression of GPR55 and the production of its ligands. The study revealed that regulation of GPR55 occurs predominantly in the context of immune activation pointing towards the role of the receptor in response to pathogens and in immune cell lineage determination. Additionally, it was revealed that there is almost no overlap between the experimental conditions affecting the expression of GPR55 and those modulating agonist production. The capacity to synthesize LPI was enhanced in various types of tumors, indicating that cancer cells can hijack the motility-related activity of GPR55 to increase aggressiveness. Conditions favoring accumulation of PACAP-derived peptides were different than those for LPI and were mainly related to differentiation. This indicates a different function of the two agonist classes and possibly the existence of a signaling bias.     

Association studies on the porcine RETN, UCP1, UCP3 and ADRB3 genes polymorphism with fatness traits

Searching for effects of candidate gene polymorphisms on fatness traits is an important goal for pig industry. In this study we evaluated polymorphism of four porcine genes involved in energy metabolism (RETN, UCP1, UCP3 and ADRB3). Moreover, their association with fat deposition traits was analyzed in two breeds (Polish Landrace, Polish Large White) and a Polish synthetic line (L990). Altogether, five SNPs were identified, including two novel ones in the 5′-flanking region of the RETN gene and a novel missense substitution in the UCP3. Distribution of these polymorphisms in the studied five breeds and the synthetic line was not uniform. Two of the analyzed SNPs: g.−178G > A in the RETN and g.946C > T in the UCP3 gene revealed a significant association with abdominal fat weight or backfat thickness. Such associations were not observed for the UCP1 or ADRB3 gene polymorphisms. Our study showed that polymorphisms of the UCP3 and RETN genes are potentially associated with porcine fatness traits.     

Extrusion of polyethylene/polypropylene blends with microfibrillar‐phase morphology

Extrusion of immiscible polymers under special conditions can lead to creation of microfibrillar‐phase morphology, ensuring significant increase of mechanical properties of polymer profiles. Polyethylene/polypropylene blend extrudates with microfibrillar‐phase morphology (polypropylene microfibrils reinforcing polyethylene matrix phase) were prepared through continuous extrusion with semihyperbolic‐converging die enabling elongation and orientation of microfibrils in flow direction. Structure of extruded profiles was examined using electron microscopy and wide‐angle X‐ray scattering. Tensile tests proved that extrudates with microfibrillar‐phase morphology show significantly higher mechanical properties than the conventional extrudates. The presented concept offers possibility of replacing the existing expensive multi‐component medical devices with fully polymeric tools. POLYM. COMPOS., 31:1427–1433, 2010. © 2009 Society of Plastics Engineers