Modeling and Analysis of Effective Ways for Improving the Reliability of Second-hand Products Sold with Warranty

Often, customers are uncertain about the performance and durability of the used/second-hand products. The warranties play an important role in reassuring the buyer. Offering the warranty implies that the dealer incurs additional costs to service any claims made by the customers. Reducing warranty costs is an issue of great interest to dealers. One way of improving the reliability and reducing the warranty servicing cost for second-hand items is through actions such as overhaul and upgrade which are carried out by the dealer or a third party. Improving actions allow the dealer to offer better warranty terms and to sell the item at a higher price. This paper deals with two effective approaches (virtual age approach and screening test approach) to decide on the reliability improvement strategies for second-hand products sold under various warranty policies (failure-free, rebate warranty, and a combination of free replacement and lump sum). A numerical example illustrates that from a dealer’s point of view, it is beneficial to carry out an improvement action only if the reduction in the warranty servicing cost is greater than the extra cost incurred due to this improvement action

Gene Expression Profiling in Gastric Mucosa from Helicobacter pylori-Infected and Uninfected Patients Undergoing Chronic Superficial Gastritis

Helicobacter pylori infection reprograms host gene expression and influences various cellular processes, which have been investigated by cDNA microarray using in vitro culture cells and in vivo gastric biopsies from patients of the Chronic Abdominal Complaint. To further explore the effects of H. pylori infection on host gene expression, we have collected the gastric antral mucosa samples from 6 untreated patients with gastroscopic and pathologic confirmation of chronic superficial gastritis. Among them three patients were infected by H. pylori and the other three patients were not. These samples were analyzed by a microarray chip which contains 14,112 cloned cDNAs, and microarray data were analyzed via BRB ArrayTools software and Ingenuity Pathways Analysis (IPA) website. The results showed 34 genes of 38 differentially expressed genes regulated by H. pylori infection had been annotated. The annotated genes were involved in protein metabolism, inflammatory and immunological reaction, signal transduction, gene transcription, trace element metabolism, and so on. The 82% of these genes (28/34) were categorized in three molecular interaction networks involved in gene expression, cancer progress, antigen presentation and inflammatory response. The expression data of the array hybridization was confirmed by quantitative real-time PCR assays. Taken together, these data indicated that H. pylori infection could alter cellular gene expression processes, escape host defense mechanism, increase inflammatory and immune responses, activate NF-κB and Wnt/β-catenin signaling pathway, disturb metal ion homeostasis, and induce carcinogenesis. All of these might help to explain H. pylori pathogenic mechanism and the gastroduodenal pathogenesis induced by H. pylori infection

Preparation of Cucurbituril Anchored Silica Gel by Cross Polymerization and Its Chromatographic Applications

A new chromatographic stationary phase has been prepared by cross polymerization between allylsilica and perallyloxycucurbit[6]uril and characterized by elemental analysis and FT-IR spectroscopy. The double end-capping has been proven to improve the separation efficiency of the cucurbituril-based stationary phase material. The first end-capping was carried out when allylsilica was made. The second end-capping was done as the final step of the whole process, and the use of a mixture of hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS) as an end-capping reagent was found better than the use of only HMDS or TMCS. Our stationary phase has shown generally good results in separation of nonpolar and polar analytes. This phase showed even better separation performance than the commercial C18 phase for the case where host-guest chemistry was properly incorporated in solute retention.X1119sciescopuskc

Intracellular domains of amyloid precursor-like protein 2 interact with CP2 transcription factor in the nucleus and induce glycogen synthase kinase-3 beta expression

Amyloid precursor protein (APP) is a member of a gene family that includes two APP-like proteins, APLP1 and 2. Recently, it has been reported that APLP1 and 2 undergo presenilin-dependent gamma-secretase cleavage, as does APP, resulting in the release of an similar to 6 kDa intracellular C-terminal domain (ICD), which can translocate into the nucleus. In this study, we demonstrate that the APLP2-ICDs interact with CP2/LSF/LBP1 (CP2) transcription factor in the nucleus and induce the expression of glycogen synthase kinase 3 beta (GSK-3 beta), which has broad-ranged substrates such as tau- and beta-catenin. The significance of this finding is substantiated by the in vivo evidence of the increase in the immunoreactivities for the nuclear C-terminal fragments of APLP2, and for GSK-3 beta in the AD patients' brain. Taken together, these results suggest that APLP2-ICDs contribute to the AD pathogenesis, by inducing GSK-3 beta expression through the interaction with CP2 transcription factor in the nucleus.X1129sciescopu

Soft x-ray absorption and photoemission spectroscopy study of superoxide KO2

The electronic structure of superoxide KO2 was investigated by employing soft x-ray absorption spectroscopy (XAS) and core-level photoemission spectroscopy (PES). The clean and single component was observed in both the O 1s and K 2p core-level PES spectra of KO2, which confirms the good quality of the KO2 sample employed in this work. The measured O 1s XAS spectrum was compared with the calculated density of states (DOSs), obtained from the first-principles electronic-structure calculations that include both the spin-orbit (SO) effect and the on-site Coulomb interaction (U) between O 2p electrons. In the O 1s XAS, both the unoccupied O 2p antibonding pi(g) and sigma(u) states are identified. It is found that the unoccupied states, observed in the O 1s XAS, agree reasonably well with the calculated DOSs, which suggests the importance of the SO and U effects for KO2 having the high-symmetry tetragonal structure.X111311sciescopu