Identification of Receptor Tyrosine Kinase, Discoidin Domain Receptor 1 (DDR1), as a Potential Biomarker for Serous Ovarian Cancer

Ovarian cancer, one of the most common gynecological malignancies, has an aggressive phenotype. It is necessary to develop novel and more effective treatment strategies against advanced disease. Protein tyrosine kinases (PTKs) play an important role in the signal transduction pathways involved in tumorigenesis, and represent potential targets for anticancer therapies. In this study, we performed cDNA subtraction following polymerase chain reaction (PCR) using degenerate oligonucleotide primers to identify specifically overexpressed PTKs in ovarian cancer. Three PTKs, janus kinase 1, insulin-like growth factor 1 receptor, and discoidin domain receptor 1 (DDR1), were identified and only DDR1 was overexpressed in all ovarian cancer tissues examined for the validation by quantitative real-time PCR. The DDR1 protein was expressed in 63% (42/67) of serous ovarian cancer tissue, whereas it was undetectable in normal ovarian surface epithelium. DDR1 was expressed significantly more frequently in high-grade (79%) and advanced stage (77%) tumors compared to low-grade (50%) and early stage (43%) tumors. The expression of the DDR1 protein significantly correlated with poor disease-free survival. Although its functional role and clinical utility remain to be examined in future studies, our results suggest that the expression of DDR1 may serve as both a potential biomarker and a molecular target for advanced ovarian cancer.     

Viscoelastic behavior of poly(butyl methacrylate) densely grafted on silica nanoparticles

A series of poly(butyl methacrylate)s (PBMAs) with various molar masses (33 000–270 000 g mol^?1), which were densely grafted on fumed silica nanoparticles (PBMA–SiO₂), were synthesized by surface‐initiated atom transfer radical polymerization. The dynamic viscoelastic behavior of PBMA–SiO₂ was systematically investigated in the solid and molten states with oscillatory strains, and compared to that of a conventional nanocomposite (PBMA/SiO₂). The storage moduli of PBMA–SiO₂ and PBMA/SiO₂ are equivalent in the solid state, whereas the storage modulus of PBMA–SiO₂ is lower than that of PBMA/SiO₂ in the molten state, especially at high silica loading. This is because the formation of a network structure composed of the silica nanoparticles in PBMA–SiO₂ is strongly suppressed by the polymer brushes on the particles. In contrast, even at low silica loading, the PBMA–SiO₂ system exhibits a gel‐like behavior resulting from a steric repulsion between the composite particles, because all of the tethered polymers behave as bound polymers. Copyright © 2011 Society of Chemical Industry     

Effect of the Magnetostrictive Layer on Magnetoelectric Properties in Lead Zirconate Titanate/Terfenol-D Laminate Composites

Magnetoelectric laminate composites of piezoelectric/magnetostrictive materials were prepared by stacking and bonding together a PZT disk and two layers of Terfenol-D disks with different directions of magnetostriction. These composites were studied to investigate (i) dependence on the magnetostriction direction of the Terfenol-D disk and (ii) dependence on the direction of the applied ac magnetic field. Three different types of assemblies were prepared by using two types of disks: one with magnetostriction along the radial direction, the other with magnetostriction along the thickness direction. The maximum magnetoelectric voltage coefficient (d E /d H ) of 5.90 V/cm·Oe was obtained for a design where the composite was made by two Terfenol-D layers with a radial magnetostriction direction.     

Phase Relations and Volume Changes of Hafnia under High Pressure and High Temperature

Using multi-anvil high-pressure devices and synchrotron radiation, X-ray in situ observations of HfO₂ under high pressure and high temperature have been performed to investigate its phase relations and compression behavior. An orthorhombic phase (orthoI) is stable from 4 to 14.5 GPa below 1250°–1400°C and transforms to a tetragonal phase, which is one of the high-temperature forms of HfO₂, above these temperatures. Another orthorhombic phase (orthoII) with a cotunnite-type structure appears above 14.5 GPa. OrthoII is stable up to 1800°C at 21 GPa. OrthoII is quenchable to ambient conditions. The orthoI-to-orthoII transition is accompanied by ∼8 vol% decrease. The bulk moduli of orthoI and orthoII at room temperature are 220 and 312 GPa, respectively. This low compressibility of orthoII indicates that it is a potential candidate for very hard materials.     

Role of Metabolism in Bone Development and Homeostasis

Carbohydrates, fats, and proteins are the underlying energy sources for animals and are catabolized through specific biochemical cascades involving numerous enzymes. The catabolites and metabolites in these metabolic pathways are crucial for many cellular functions; therefore, an imbalance and/or dysregulation of these pathways causes cellular dysfunction, resulting in various metabolic diseases. Bone, a highly mineralized organ that serves as a skeleton of the body, undergoes continuous active turnover, which is required for the maintenance of healthy bony components through the deposition and resorption of bone matrix and minerals. This highly coordinated event is regulated throughout life by bone cells such as osteoblasts, osteoclasts, and osteocytes, and requires synchronized activities from different metabolic pathways. Here, we aim to provide a comprehensive review of the cellular metabolism involved in bone development and homeostasis, as revealed by mouse genetic studies.     

Effect of Additives on the Electromechanical Properties of Pb(Zr,Ti)O3–Pb(Y2/3W1/3)O3 Ceramics

Dielectric and piezoelectric properties of 0.02Pb(Y_2/3W_1/3)O₃ 0.98Pb(Zr0.52Ti0.48)O3 ceramics doped with additives (Nb₂O₅, La₂O₃, MnO₂, and Fe₂O₃) were investigated. The grain sizes of these ceramics decreased with increasing amounts of additives. For additions of MnO₂ and Fe₂O₃, dielectric losses decreased, while for Nb₂O₅ and La₂O₃, these values increased. The maximum values of the mechanical quality factor Q_m were found to be 956 and 975 for additions of 0.9 wt% Fe₂O₃ and 0.7 wt% MnO₂, respectively, but donor dopants (Nb₂O₅ and La₂O₃) did not change the values of Q_m . On the other hand, the piezoelectric constant d₃₃ and the electromechanical coupling factor k_p decreased with additions of MnO₂ and Fe₂O₃, but improved with additions of Nb₂O₅ and La₂O₃.     

Structurally Diverse Polyamines: Solid‐Phase Synthesis and Interaction with DNA

A versatile solid‐phase approach based on peptide chemistry was used to construct four classes of structurally diverse polyamines with modified backbones: linear, partially constrained, branched, and cyclic. Their effects on DNA duplex stability and structure were examined. The polyamines showed distinct activities, thus highlighting the importance of polyamine backbone structure. Interestingly, the rank order of polyamine ability for DNA compaction was different to that for their effects on circular dichroism and melting temperature, thus indicating that these polyamines have distinct effects on secondary and higher‐order structures of DNA.     

CuI and H2O2 Inactivate and FeII Inhibits [Fe]‐Hydrogenase at Very Low Concentrations

[Fe]‐Hydrogenase (Hmd) catalyzes reversible hydride transfer from H₂. It harbors an iron‐guanylylpyridinol as a cofactor with an Fe^II that is ligated to one thiolate, two COs, one acyl‐C, one pyridinol‐N, and solvent. Here, we report that Cu^I and H₂O₂ inactivate Hmd (half‐maximal rates at 1 μM Cu^I and 20 μM H₂O₂) and that Fe^II inhibits the enzyme with very high affinity (K_i=40 nM ). Infrared and EPR studies together with competitive inhibition studies with isocyanide indicated that Cu^I exerts its inhibitory effect most probably by binding to the active site iron‐thiolate ligand. Using the same methods, it was found that H₂O₂ binds to the active‐site iron at the solvent‐binding site and oxidizes Fe^II to Fe^III. Also it was shown that Fe^II reversibly binds away from the active site iron, with binding being competitive to the organic hydride acceptor; this inhibition is specific for Fe^II and is reminiscent of that for the [FeFe]‐hydrogenase second iron, which specifically interacts with H₂.     

Characterization of piezoelectric ceramics using the burst/transient method with resonance and antiresonance analysis

In this paper, a comprehensive methodology for characterizing the high power resonance behavior of bulk piezoelectric ceramics using the burst method is described. In the burst method, the sample is electrically driven at its resonance frequency, and then either a short circuit or an open circuit condition is imposed, after which the vibration decays at the resonance or antiresonance frequency, respectively. This decay can be used to measure the quality factor in either of these conditions. The resulting current in the short circuit vibration condition is related to the vibration velocity through the “force factor.” The generated voltage in the open circuit vibration condition corresponds to the displacement by the “voltage factor.” The force factor and the voltage factor are related to material properties and physical dimensions of the sample. Using this method, the high power behavior of the permittivity, compliance, effective piezoelectric charge constant, electromechanical coupling factor, and material losses can be determined directly by measuring the resonance (short circuit) and antiresonance (open circuit) frequencies, their corresponding quality factors, the force factor A, and the voltage factor B. The experimental procedure to apply this method is described and demonstrated on commercially available hard and semi‐hard PZT materials of geometry.     

The micro-nanoformability of Pt-based metallic glass and the nanoforming of three-dimensional structures

Pt_48.75Pd_9.75Cu_19.5P₂₂ amorphous alloy exhibits obvious glass transition behavior at a temperature of T_g=502 K, which is below the crystallization temperature T_x=588 K, and develops a supercooled liquid state in a wide temperature range of ΔT_x (=T_x−T_g)=86 K. The present paper investigates the macroscopic and microscopic deformation behavior of the material and the possibility of micro-nano forming as a fabrication method and material for nano-devices. On a macroscopic scale, the material exhibits a Newtonian viscous flow in a supercooled liquid state. An index of the microformability is also evaluated by the geometrical transferability of a die shape to the material. For this study, we fabricated V-grooved micro dies of (100) Si by a silicon process. The V-groove dies are from 100 nm to 1 μm wide. The material exhibits superior formability on micrometer and nanometer scales and may possibly be applied to micro-nanomaterials for micro-nano devices.