Study of the Heating-and-Pressing Separation Process of Laminated Object Manufacturing (LOM)

To improve hot-pressing process currently employed by the laminated object manufacturing (LOM), an innovated heating-and-pressing separation system is proposed, and heat transfer problems of this system is investigated. A thermal model is first established. It is solved numerically by the finite element method (FEM) software ANSYS, and verified by experiments. According to the numerical solution under various operating conditions, it is suggested that if the temperature and the moving speed of the heater are both increased, the depth of the heat affected laminates will be reduced. The processing time will be shortened and the manufacture efficiency will be promoted. Through analysis, it is concluded that, to obtain finished parts of high quality, the appropriate distance between the roller and the heater can be determined.Mechanical Engineerin

How to encourage customers to use legal software

This study attempts to identify customer retention strategies for legal software and discusses their effectiveness for three consumer groups (stayers, dissatisfied switchers, and satisfied switchers). Although previous studies propose several antipirating strategies, they do not discuss how to enhance customer intentions to use legal software, which is crucial for software companies. The authors provide four generic retention strategies developed from both antipiracy and customer loyalty literature. The results indicate lower-pricing, legal, communication, and product strategies all enhance customer purchase intentions toward legal software. The lower-pricing strategy is more useful for stayers and dissatisfied switchers, and the communication strategy is most useful for dissatisfied switchers. Both the legal and product strategies have similar impacts on purchase intentions across the three segments. From a firm perspective, a product strategy is most worthwhile and useful across all segments

Novel hybrid vesicles co-assembled from a cationic lipid and PAAc-g-mPEG with pH-triggered transmembrane channels for controlled drug release

This work presents an important example of novel hybrid vesicles with pH-triggered transmembrane channels prepared by co-assembly of poly(acrylic acid)-g-poly(monomethoxy ethylene glycol) (PAAc-g-mPEG) with a cationic lipid, didodecyldimethylammonium bromide (DDAB), via electrostatic interaction for effective doxorubicin (DOX) release

The signals of FGFs on the neurogenesis of embryonic stem cells

<p>Abstract</p> <p>Background</p> <p>Neural induction is a complex process and the detailed mechanism of FGF-induced neurogenesis remains unclear.</p> <p>Methods</p> <p>By using a serum-free neural induction method, we showed that FGF1 dose-dependently promoted the induction of Sox1/N-cadherin/nestin triple positive cells, which represent primitive neuroblasts, from mouse embryonic stem (ES) cells.</p> <p>Results</p> <p>We demonstrated that FGF1, FGF2, and FGF4, but not FGF8b, enhanced this neurogenesis. Especially, FGF-enhanced neurogenesis is not mediated through the rescue of the apoptosis or the enhancement of the proliferation of Sox1⁺cells. We further indicated that the inactivation of c-Jun N-terminal kinase-1 (JNK-1) and extracellular signal-related kinase-2 (ERK-2), but not p38 mitogen-activated protein kinase (MAPK), inhibited the neural formation through the inhibition of ES differentiation, but not through the formation of endomesodermal cells.</p> <p>Conclusions</p> <p>These lines of evidence delineated the roles of FGF downstream signals in the early neural differentiation of ES cells.</p

VOC amounts in ambient areas of a high-technology science park in Taiwan: their reciprocal correlations and impact on inhabitants

This study presents bihourly, seasonal, and yearly concentration changes in volatile organic compounds (VOCs) in the inlet and effluent water of the wastewater treatment plant (WWTP) of a high-technology science park (HTIP) in Taiwan, with the VOC amounts at different sites correlated geologically. This research adopted a combination of two systems, solid-phase microextraction with a gas chromatography/flame ionization detector and an assembly of purge and trap coupled with gas chromatography/mass spectrometry, to monitor polar and nonpolar VOCs in wastewater. This paper investigated the total VOCs, acetone, isopropyl alcohol (IPA), and dimethylsulfide (DMS) concentrations in real water samples collected in the ambient area of the HTIP. The major contents of VOCs measured in the effluent of the WWTP in the HTIP and the surrounding river region were DMS (14-176 ppb), acetone (5-95 ppb), and IPA (15-316 ppb). In comparison with the total VOCs in the inlet wastewater of the WWTP, no corresponding relationship for total VOC concentration in the wastewater was observed between the inlet water and effluent water of the WWTP. The peak VOC concentrations appeared in the third season, and the correlation of different VOC amounts reflects the production situation of the factories. In addition, VOC concentrations at different sites indicate that the Ke-Ya River is seemingly an effective channel for transporting wastewater to its final destination. The data are good indications for the management of environmental pollution near the HTIP

Ginkgo biloba extract attenuates oxLDL-induced oxidative functional damages in endothelial cells

Ou HC, Lee WJ, Lee IT, Chiu TH, Tsai KL, Lin CY, Sheu WH. Ginkgo biloba extract attenuates oxLDL-induced oxidative functional damages in endothelial cells. J Appl Physiol 106: 1674-1685, 2009. First published February 19, 2009; doi:10.1152/japplphysiol.91415.2008.-Atherosclerosis is a chronic inflammatory process with increased oxidative stress in vascular endothelium. Ginkgo biloba extract (GbE), extracted from Ginkgo biloba leaves, has commonly been used as a therapeutic agent for cardiovascular and neurological disorders. The aim of this study was to investigate how GbE protects vascular endothelial cells against the proatherosclerotic stressor oxidized low-density lipoprotein (oxLDL) in vitro. Human umbilical vein endothelial cells (HUVECs) were incubated with GbE (12.5-100 mu g/ml) for 2 h and then incubated with oxLDL (150 mu g/ml) for an additional 24 h. Subsequently, reactive oxygen species (ROS) generation, antioxidant enzyme activities, adhesion to monocytes, cell morphology, viability, and several apoptotic indexes were assessed. Our data show that ROS generation is an upstream signal in oxLDL-treated HUVECs. Cu,Zn-SOD, but not Mn-SOD, was inactivated by oxLDL. In addition, oxLDL diminished expression of endothelial NO synthase and enhanced expression of adhesion molecules (ICAM, VCAM, and E-selectin) and the adherence of monocytic THP-1 cells to HUVECs. Furthermore, oxLDL increased intracellular calcium, disturbed the balance of Bcl-2 family proteins, destabilized mitochondrial membrane potential, and triggered subsequent cytochrome c release into the cytosol and activation of caspase-3. These detrimental effects were ameliorated dose dependently by GbE (P < 0.05). Results from this study may provide insight into a possible molecular mechanism underlying GbE suppression of the oxLDL-mediated vascular endothelial dysfunction

Studying Paths of Participation in Viral Diffusion Process

Authors propose a conceptual model of participation in viral diffusion process composed of four stages: awareness, infection, engagement and action. To verify the model it has been applied and studied in the virtual social chat environment settings. The study investigates the behavioral paths of actions that reflect the stages of participation in the diffusion and presents shortcuts, that lead to the final action, i.e. the attendance in a virtual event. The results show that the participation in each stage of the process increases the probability of reaching the final action. Nevertheless, the majority of users involved in the virtual event did not go through each stage of the process but followed the shortcuts. That suggests that the viral diffusion process is not necessarily a linear sequence of human actions but rather a dynamic system.Comment: In proceedings of the 4th International Conference on Social Informatics, SocInfo 201

Anomalous metamagnetism in the low carrier density Kondo lattice YbRh3Si7

We report complex metamagnetic transitions in single crystals of the new low carrier Kondo antiferromagnet YbRh3Si7. Electrical transport, magnetization, and specific heat measurements reveal antiferromagnetic order at T_N = 7.5 K. Neutron diffraction measurements show that the magnetic ground state of YbRh3Si7 is a collinear antiferromagnet where the moments are aligned in the ab plane. With such an ordered state, no metamagnetic transitions are expected when a magnetic field is applied along the c axis. It is therefore surprising that high field magnetization, torque, and resistivity measurements with H||c reveal two metamagnetic transitions at mu_0H_1 = 6.7 T and mu_0H_2 = 21 T. When the field is tilted away from the c axis, towards the ab plane, both metamagnetic transitions are shifted to higher fields. The first metamagnetic transition leads to an abrupt increase in the electrical resistivity, while the second transition is accompanied by a dramatic reduction in the electrical resistivity. Thus, the magnetic and electronic degrees of freedom in YbRh3Si7 are strongly coupled. We discuss the origin of the anomalous metamagnetism and conclude that it is related to competition between crystal electric field anisotropy and anisotropic exchange interactions.Comment: 23 pages and 4 figures in the main text. 7 pages and 5 figures in the supplementary materia