The Relationship between the Beveridge-Nelson Decomposition andUnobserved Component Models with Correlated Shocks

Many researchers believe that the Beveridge-Nelson decomposition leads to permanent and transitory components whose shocks are perfectly negatively correlated. Indeed, some even consider it to be a property of the decomposition. We demonstrate that the Beveridge-Nelson decomposition does not provide definitive information about the correlation between permanent and transitory shocks in an unobserved components model. Given an ARIMA model describing the evolution of U.S. real GDP, we show that there are many state space representations that generate the Beveridge-Nelson decomposition. These include unobserved components models with perfectly correlated shocks and partially correlated shocks. In our applications, the only knowledge we have about the correlation is that it lies in a restricted interval that does not include zero. Although the filtered estimates of the trend and cycle are identical for models with different correlations, the observationally equivalent unobserved components models produce different smoothed estimates.

Tuning the electronic band structure of PCBM by electron irradiation

Tuning the electronic band structures such as band-edge position and bandgap of organic semiconductors is crucial to maximize the performance of organic photovoltaic devices. We present a simple yet effective electron irradiation approach to tune the band structure of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) that is the most widely used organic acceptor material. We have found that the lowest unoccupied molecular orbital (LUMO) level of PCBM up-shifts toward the vacuum energy level, while the highest occupied molecular orbital (HOMO) level down-shifts when PCBM is electron-irradiated. The shift of the HOMO and the LUMO levels increases as the irradiated electron fluence increases. Accordingly, the band-edge position and the bandgap of PCBM can be controlled by adjusting the electron fluence. Characterization of electron-irradiated PCBM reveals that the variation of the band structure is attributed to the molecular structural change of PCBM by electron irradiation

Fabrication of complete titania nanoporous structures via electrochemical anodization of Ti

We present a novel method to fabricate complete and highly oriented anodic titanium oxide (ATO) nano-porous structures with uniform and parallel nanochannels. ATO nano-porous structures are fabricated by anodizing a Ti-foil in two different organic viscous electrolytes at room temperature using a two-step anodizing method. TiO2 nanotubes covered with a few nanometer thin nano-porous layer is produced when the first and the second anodization are carried out in the same electrolyte. However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one. TNP structure was attributed to the suppression of F-rich layer dissolution between the cell boundaries in the viscous electrolyte. The structural morphologies were examined by field emission scanning electron microscope. The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm. These TNP structures are useful to fabricate other nanostructure materials and nanodevices

Improvement in the photoelectrochemical responses of PCBM/TiO2 electrode by electron irradiation

The photoelectrochemical (PEC) responses of electron-irradiated [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/TiO2 electrodes were evaluated in a PEC cell. By coating PCBM on TiO2 nanoparticle film, the light absorption of PCBM/TiO2 electrode has expanded to the visible light region and improved the PEC responses compared to bare TiO2 electrode. The PEC responses were further improved by irradiating an electron beam on PCBM/TiO2 electrodes. Compared to non-irradiated PCBM/TiO2 electrodes, electron irradiation increased the photocurrent density and the open-circuit potential of PEC cells by approximately 90% and approximately 36%, respectively at an optimum electron irradiation condition. The PEC responses are carefully evaluated correlating with the optical and electronic properties of electron-irradiated PCBM/TiO2 electrodes

Mesenchymal stem/stromal cells precondition lung monocytes/macrophages to produce tolerance against allo- and autoimmunity in the eye

Intravenously administered mesenchymal stem/stromal cells (MSCs) engraft only transiently in recipients, but confer long-term therapeutic benefits in patients with immune disorders. This suggests that MSCs induce immune tolerance by long-lasting effects on the recipient immune regulatory system. Here, we demonstrate that i.v. infusion of MSCs preconditioned lung monocytes/macrophages toward an immune regulatory phenotype in a TNF-α–stimulated gene/protein (TSG)-6–dependent manner. As a result, mice were protected against subsequent immune challenge in two models of allo- and autoimmune ocular inflammation: corneal allotransplantation and experimental autoimmune uveitis (EAU). The monocytes/macrophages primed by MSCs expressed high levels of MHC class II, B220, CD11b, and IL-10, and exhibited T-cell–suppressive activities independently of FoxP3(+) regulatory T cells. Adoptive transfer of MSC-induced B220(+)CD11b(+) monocytes/macrophages prevented corneal allograft rejection and EAU. Deletion of monocytes/macrophages abrogated the MSC-induced tolerance. However, MSCs with TSG-6 knockdown did not induce MHC II(+)B220(+)CD11b(+) cells, and failed to attenuate EAU. Therefore, the results demonstrate a mechanism of the MSC-mediated immune modulation through induction of innate immune tolerance that involves monocytes/macrophages

Investigating the Relationship between Serum Interleukin-17 Levels and Systemic Immune-Mediated Disease in Patients with Dry Eye Syndrome

Purpose: To investigate the association between dry eye syndrome (DE) and serum levels of interleukin (IL)-17 in patients with systemic immune-mediated diseases. Methods: IL-17 and IL-23 levels were measured in the sera of patients whose tear production was <5 mm on the Schirmer test. Subjects included patients with chronic graft-versus-host disease (GVHD), rheumatoid arthritis (RA), Sjogren’s syndrome (SS), systemic lupus erythematosus (SLE), and no systemic disease. Corneal/conjunctival fluorescein staining was scored and the correlation between the score and the IL-17 level was evaluated. Results: A strong correlation existed between IL-17 level and the type of systemic disease. IL-17 was significantly elevated in patients with chronic GVHD compared to those with RA and SS. IL-17 was not detectable in patients with SLE or in those without systemic disease. IL-23 was not detected in any of the subjects. IL-17 was significantly increased in patients with high fluorescein staining scores. Conclusions: Our data suggest that IL-17 is involved in the pathogenesis of DE in patients with systemic immune-mediated diseases. Key Words: Chronic graft-versus-host disease, Dry eye syndromes, Interleukin-17, Rheumatoid arthritis, Sjogren’s syndrom

The Role of Cyclosporine and Mycophenolate in an Orthotopic Porcine-to-Rat Corneal Xenotransplantation

We performed this study to investigate the feature of rejection in porcine-to-rat corneal orthotopic transplantation and to evaluate the effect of cyclosporine and mycophenolate on the xeno-rejection. Orthotopic corneal transplantation was done at 91 Sprague-Dawley rats, and they were divided into 10 groups based on the combination of immunosuppressants including dexamethasone, cyclosporine, and mycophenolate mofetil. Graft survival was analyzed and grafted eyes were examined with Hematoxylin & Eosin and CD4 or CD8 staining. Enzyme-linked immunosorbent assays were done for interleukin-2 (IL-2), IL-4, IL-5, IL-10, and interferon (IFN)-γ in cornea, lacrimal gland, and cervical lymph nodes. The longest median survival of the immune suppressant group was 11.00±1.96 days, which showed no statistical differences compared with that of control (8.00±1.52 days). The neutrophils were prominent in the early phase but soon gave way to the monocytes. The number of CD8+ cells was higher than that of CD4+ cells. IL-2 and IFN-γ markedly increased at 10 to13 days in cornea, lacrimal glands, and cervical lymph nodes, which showed a decrease with immunosuppressants except in the cornea. In conclusion, cyclosporine and mycophenolate could not prevent the rejection in porcine to rat orthotopic corneal xenograft associated with infiltraton of CD8+ and innate immune cells

DNA Microarray-Based Gene Expression Profiling in Porcine Keratocytes and Corneal Endothelial Cells and Comparative Analysis Associated with Xeno-related Rejection

Porcine to rat corneal xenotransplantation resulted in severe inflammation and rejection of the corneal stroma, whereas an allograft showed mainly endothelial cell-associated rejection. We, therefore, investigated and compared the gene expression between porcine keratocytes and corneal endothelial cells. RNA was isolated from primary cultured porcine or human keratocytes and porcine corneal endothelial cells. Gene expression was comparatively analyzed after normalization with microarray method using Platinum pig 13 K oligo chip (GenoCheck Co., Ltd., Ansan, Korea). Real-time polymerase chain reaction (PCR) was performed for C1R, CCL2, CXCL6, and HLA-A in porcine keratocytes and corneal endothelial cells. As a result, upregulated expression more than 2 folds was observed in 1,162 genes of porcine keratocytes versus porcine endothelial cells. Among the immune-regulatory genes, SEMA3C, CCL2, CXCL6, F3, HLA-A, CD97, IFI30, C1R, and G1P3 were highly expressed in porcine keratocytes, compared to porcine corneal endothelial cells or human keratocytes. When measured by real-time PCR, the expression of C1R, CCL2, and HLA-A was higher in porcine keratocytes compared to that in porcine corneal endothelial cells. In conclusion, the increased expression of C1R, CCL2, and HLA-A genes in porcine keratocytes might be responsible for the stromal rejection observed in a porcine to rat corneal xenotransplantation