The detailed mechanism of electronic bipolar resistance switching (BRS) in the Pt/TiO(2)/Pt structure was examined. The conduction mechanism analysis showed that the trap-free and trap-mediated space-charge-limited conduction (SCLC) governs the low and high resistance state of BRS, respectively. The SCLC was confirmed by fitting the current-voltage characteristics of low and high resistance states at various temperatures. The BRS behavior originated from the asymmetric potential barrier for electrons escaping from, and trapping into, the trap sites with respect to the bias polarity. This asymmetric potential barrier was formed at the interface between the trap layer and trap-free layer. The detailed parameters such as trap density, and trap layer and trap-free layer thicknesses in the electronic BRS were evaluated. This showed that the degradation in the switching performance could be understood from the decrease and modified distribution of the trap densities in the trap layer.

IkappaB kinase (IKK) and Jun N-terminal kinase (Jnk) signaling modules are important in the synthesis of immune effector molecules during innate immune responses against lipopolysaccharide and peptidoglycan. However, the regulatory mechanisms required for specificity and termination of these immune responses are unclear. We show here that crosstalk occurred between the drosophila Jnk and IKK pathways, which led to downregulation of each other's activity. The inhibitory action of Jnk was mediated by binding of drosophila activator protein 1 (AP1) to promoters activated by the transcription factor NF-kappaB. This binding led to recruitment of the histone deacetylase dHDAC1 to the promoter of the gene encoding the antibacterial protein Attacin-A and to local modification of histone acetylation content. Thus, AP1 acts as a repressor by recruiting the deacetylase complex to terminate activation of a group of NF-kappaB target genes.

This study examined the effects of electrical forming methods on the bipolar resistance switching (BRS) behavior in Pt/TiO(2)/Pt sandwich structures. The BRS is confined to a region near the ruptured end of conducting nanofilaments, which are composed of a Ti(n)O(2n-1) Magnéli phase formed by electroforming. The intermediate phase with an oxygen vacancy concentration between the insulating TiO(2) and the residual conducting filament that formed at the interface region was considered to be the switching layer (SL). The change in filament shape caused by a variation in the compliance current during filament formation resulted in a different filament rupture location and SL configuration. Precise control of the filament formation and rupture process resulted in SLs connected in an anti-parallel configuration. It was possible to reconfigure the SLs in the same fashion without any restraints, which allowed an unlimited memristive operation to be achieved. This paper presents a new technique in voltage sweep mode that applies a compliance current as a tool to achieve a memristor with unlimited operation.

The therapeutic effect of bone marrow stimulation techniques (BSTs) is mainly attributed to the role of mesenchymal stem cells (MSCs) from the bone marrow. However, no studies have directly shown the amount of MSCs drained by BSTs. This study hypothesized that differences in the opening of subchondral bone affect the number of MSCs drained from the bone marrow. We purposed that as the exposed area and hole size of BSTs vary, the number of MSCs drained out was measured. Three groups of different BSTs were designed that have variations in the sizes of total exposed area and individual holes. Three different BSTs using a curette, 1.5-and 0.8-mm awls were carried out on the full-thickness femoral cartilage defect of young rabbits. After BST, the number of MSCs in the blood clot was measured by CFU-Fs assay. As the size of the total exposed area increased, so did the number of MSCs obtained. The number of MSCs drained from bone marrow may vary depending on different BSTs and this could affect therapeutic efficacy of cartilage defect. As current microfracture (MF) method cannot drain the most MSCs clinically, more improved surgery technique is needed. ß

Bone marrow stimulation techniques (BSTs) are widely used in clinics to treat cartilage defects, but yet have a critical limitation from the loss of blood clots. In this work, a novel cartilage extracellular matrix (CECM) membrane is developed to protect blood clots after BSTs. The CECM membrane was made of ECM fabricated naturally by cultured porcine chondrocytes, and then decellularized and multi-layered to confer optimal mechanical strength. Highly compatible with cells, the CECM membrane did not show any cytotoxicity or immune responses in vivo. The CECM membrane was very thin (30-60 µ m thick) and bendable, but had good tensile strength (85.64 N), suitable for protecting blood clots from leakage in rabbit cartilage defect. Moreover, the CECM membrane showed low but enough diffusion coeffi cient to allow delivery of small proteins in synovial fl uid into the repaired tissue. In a beagle model, covering the cartilage defect with the CECM membrane after BST generated more hyaline cartilage-like tissues than the BST alone in histology and chemical analyses at 18 weeks. Its ICRS score was approximately 2.5 times higher than that of the BST alone. Therefore, the CECM membrane is proposed as a useful tool that can improve the outcome of BSTs to treat cartilage defects.