Hedgehog Signaling Regulates the Survival of Gastric Cancer Cells by Regulating the Expression of Bcl-2

Gastric cancer is the second most common cause of cancer deaths worldwide. The underlying molecular mechanisms of its carcinogenesis are relatively poorly characterized. Hedgehog (Hh) signaling, which is critical for development of various organs including the gastrointestinal tract, has been associated with gastric cancer. The present study was undertaken to reveal the underlying mechanism by which Hh signaling controls gastric cancer cell proliferation. Treatment of gastric cancer cells with cyclopamine, a specific inhibitor of Hh signaling pathway, reduced proliferation and induced apoptosis of gastric cancer cells. Cyclopamine treatment induced cytochrome c release from mitochondria and cleavage of caspase 9. Moreover, Bcl-2 expression was significantly reduced by cyclopamine treatment. These results suggest that Hh signaling regulates the survival of gastric cancer cells by regulating the expression of Bcl-2.     

Effect of the dehydrogenation speed and Nd content on the microstructure and magnetic properties of HDDR processed Nd-Fe-B magnets

The effect of Nd content and dehydrogenation speed on the microstructure and magnetic properties of hydrogenation-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B magnetic powders was studied. The Nd_xB_6.4Ga_0.3Nb_0.2Fe_bal (x=12.5–13.5, at.%) mold casting alloys were subjected to HDDR process after homogenization heat treatment. During desorption-recombination stage, dehydrogenation speed and time were systematically changed to control the speed of the desorption-recombination reaction. The higher Nd content resulted in better magnetic properties of the HDDR powder, and this was attributed to the thicker and more uniform Nd-rich phase at grain boundaries. It was also confirmed that the slow dehydrogenation speed could maximize the effect of high Nd content on the magnetic properties of HDDR powder. At the optimized dehydrogenation speed, the coercivity and remanence was 15.3 kOe and 13.0 kG, respectively, at 12.9 at.% Nd content, which resulted in a (BH)_max of 36.8 MGOe.     

On the rule-of-mixtures of the hardening parameters in TWIP-cored three-layer steel sheet

Although twinning-induced plasticity (TWIP) steels have high tensile strength with high strain hardening and large uniform elongation due to the formation of deformation twins during plastic deformation, sheet formabilities of TWIP steels are relatively poor. In this study, to overcome this problem, TWIP-cored three-layer architectured steel sheets are produced using cladding with low carbon steel sheaths. For an optimum design of layer architectured materials, strain hardening exponent n and strain rate sensitivity m of the layer sheets are theoretically and experimentally investigated. The forced-based rule-of-mixtures well reproduces the experimental values of the equivalent n and m. Contrary to the conventional rule-of-mixtures, the equivalent n and m of the TWIP-cored mild steel-sheath layered sheets are governed not only by volume fractions and n and m of parent materials but also by the strength of strong layer.     

Real time monitoring of tool breakage in a milling operation using a digital signal processor

A monitoring system that can detect tool breakage and chipping in real time was developed using a digital signal processor (DSP) board in a face milling operation. An autoregressive (AR) model and a band energy method were used to extract the features of tool states from cutting force signals. Then, two artificial neural networks, which have a parallel processing capability, were embedded on the DSP board to discriminate different malfunction states from features obtained by each of the two methods of signal processing. In experiments, we found that feature parameters extracted by AR modeling were more accurate indicators of malfunctions in the process than those from the band energy method, although the computing speed is slower. By using the selected features, we were able to monitor malfunctions in real time.     

Microstructure,Tensile and Fatigue Properties of Al–5 wt.%Mg Alloy Manufactured by Twin Roll Strip Casting

This study investigated the microstructure, tensile and fatigue properties of Al–5 wt.%Mg alloy manufactured by twin roll strip casting. Strips cast as a fabricated (F) specimen and a specimen heat treated (O) at 400 °C/5 h were produced and compared. In the F specimen, microstructural observation discovered clustered precipitates in the center area, while in the O specimen precipitates were relatively more evenly distributed. Al, Al₆(Mn, Fe), Mg₂Al₃ and Mg₂Si phases were observed. However, most of the Mg₂Al₃ phase in the heat-treated O specimen was dissolved. A room temperature tensile test measured yield strength of 177.7 MPa, ultimate tensile strength of 286.1 MPa and elongation of 11.1% in the F specimen and 167.7 MPa (YS), 301.5 MPa (UTS) and 24.6% (EL) in the O specimen. A high cycle fatigue test measured a fatigue limit of 145 MPa in the F specimen and 165 MPa in the O specimen, and the O specimen achieved greater fatigue properties in all fatigue stress conditions. The tensile and fatigue fracture surfaces of the above-mentioned specimens were observed, and this study attempted to investigate the tensile and fatigue deformation behavior of strip cast Al–5 wt.%Mg based on the findings.     

Warpage of a large‐sized orthogonal stiffened plate produced by injection molding and injection compression molding

Rectangular plates of the size of 1800 × 600 × 12 mm³ and 1200 × 600 × 12 mm³ were selected for injection molding and injection compression molding, respectively, in order to investigate warpage characteristics of the large‐sized polymer plates with orthogonal stiffener. To determine the mold system and to reduce warpage of the specimen, numerical analyses for injection molding and injection compression molding were performed by using a commercial simulation code. Experiments were performed to verify the suggested mold system and warpage of the specimen. Relatively large warpage of the injection molded product was observed and small warpage of the injection compression molded product was generated. Compression force of the injection compression molding was only 6% of the clamp force of the injection molding. Warpage of the product was reduced significantly by using the injection compression molding. The injection compression molding will be used to substitute expensive and disused wood forms with inexpensive and recyclable polymer plates for concrete casting. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Residual stress analysis of an aircraft landing gear part using neutron diffraction

The residual stress of a landing gear part of a fighter jet that has a frequent practice of takeoff and landing was evaluated for the safety. The sample was a cylindrical steel bar with a 22.2 mm diameter and 55 mm length used to fix the main landing gear to the aircraft body. For a deep measurement up to 6 mm, we used a neutron beam. From the measurements, the tensile and compressive strain in the axial direction were observed around one side of the pin hole which was across the steel bar vertically with an 8 mm diameter. The strain distribution along the length of the bar presented a similar tendency through the thickness and a larger value on the surface. The maximum value of the residual stress around the pin hole was about 100 MPa. However, there was no strain on the opposite side of the pin hole. From the results, it may be surmised that the steel bar received a steady force in one direction around the pin hole, however the force was weak and affected a small limited area and thus not influence on the steel bar on the whole.     

Enhancement of surface quality in ultrasonic machining of glass using a sacrificing coating

We present a new fabrication method that enables precision hole machining to be achieved by sacrificing the coating on the substrate in ultrasonic machining (USM). A hard wax coating is deposited on the glass substrate, and holes are precisely fabricated in the coated glass using USM. Finally, a wax coating is removed using a cleaning process. The wax coating protects the surface of the glass so that cracks are generated in the wax rather than on the surface. The surface accuracy of the glass substrate is evaluated at the hole entrance using the new tools in USM as a function of the thickness of the coating. The entrance diameters of the machined holes and the machining forces at the beginning of cutting are measured as a function of the thickness of the coating. The entrance cracks and out-of-roundness of the machined holes are generated in the sacrificed coating on the glass substrate; hence, the surface quality of the glass holes is enhanced in USM.     

Senescence Marker Protein 30 (SMP30): A Novel Pan-Species Diagnostic Marker for the Histopathological Diagnosis of Breast Cancer in Humans and Animals

Senescence marker protein 30 (SMP30) is a cell survival factor playing an important role in vitamin C synthesis and antiapoptosis. Moreover, its cytoprotective role suggests a possibility to be related to cancer cell survival. Mammary carcinoma is a common cancer in both humans and animals. Because of its histopathological diversity, especially in the early stage, histopathological diagnosis may be complicated; therefore, a diagnostic marker is helpful for confirmation. The present study analyzed the expression pattern of SMP30 in mammary carcinoma in humans, dogs, and cats. Immunohistochemistry, immunofluorescence, and western blot analysis were used to investigate SMP30 expression patterns. The expression was specifically observed in neoplastic glandular epithelial cells. The expression increased with the malignancy of glandular epithelial cells with a highly proliferative status. However, SMP30 expression was low in normal mammary gland tissues or well-differentiated adenoma tissues. The patterns were consistently reproduced in canine primary mammary carcinoma cells and MCF-7 and MDA-MB-231 human carcinoma cell lines. This study provides useful information to understand SMP30 expression in various stages of mammary carcinoma and to suggest its utility as a pan-species diagnostic marker, thereby helping to establish strategies for diagnosing mammary carcinoma in several species.     

Environmental Enrichment Enhances Cav 2.1 Channel-Mediated Presynaptic Plasticity in Hypoxic–Ischemic Encephalopathy

Hypoxic–ischemic encephalopathy (HIE) is a devastating neonatal brain condition caused by lack of oxygen and limited blood flow. Environmental enrichment (EE) is a classic paradigm with a complex stimulation of physical, cognitive, and social components. EE can exert neuroplasticity and neuroprotective effects in immature brains. However, the exact mechanism of EE on the chronic condition of HIE remains unclear. HIE was induced by a permanent ligation of the right carotid artery, followed by an 8% O₂ hypoxic condition for 1 h. At 6 weeks of age, HIE mice were randomly assigned to either standard cages or EE cages. In the behavioral assessments, EE mice showed significantly improved motor performances in rotarod tests, ladder walking tests, and hanging wire tests, compared with HIE control mice. EE mice also significantly enhanced cognitive performances in Y-maze tests. Particularly, EE mice showed a significant increase in Ca_v 2.1 (P/Q type) and presynaptic proteins by molecular assessments, and a significant increase of Ca_v 2.1 in histological assessments of the cerebral cortex and hippocampus. These results indicate that EE can upregulate the expression of the Ca_v 2.1 channel and presynaptic proteins related to the synaptic vesicle cycle and neurotransmitter release, which may be responsible for motor and cognitive improvements in HIE.