RESUMO
Recently, organometallic and all-inorganic halide perovskites (HPs) have become promising materials for resistive switching (RS) nonvolatile memory devices with low power consumption because they show current-voltage hysteresis caused by fast ion migration. However, the toxicity and environmental pollution potential of lead, a common constituent of HPs, has limited the commercial applications of HP-based devices. Here, RS memory devices based on lead-free all-inorganic cesium tin iodide (CsSnI3) perovskites with temperature tolerance are successfully fabricated. The devices exhibit reproducible and reliable bipolar RS characteristics in both Ag and Au top electrodes (TEs) with different switching mechanisms. The Ag TE devices show filamentary RS behavior with ultralow operating voltages (<0.15 V). In contrast, the Au TE devices have interface-type RS behavior with gradual resistance changes. This suggests that the RS characteristics are attributed to either the formation of metal filaments or the ion migration of defects in HPs under applied electric fields. These distinct mechanisms may permit the opportunity to design devices for specific purposes. This work will pave the way for lead-free all-inorganic HP-based nonvolatile memory for commercial application in HP-based devices.
RESUMO
BACKGROUND: Previously, we reported that ChondorT showed significant anti-arthritis and anti-inflammatory effects. ChondroT, a new herbal medication, consists of the water extracts of Osterici Radix, Lonicerae Folium, Angelicae Gigantis Radix, Clematidis Radix, and Phellodendri Cortex (6:4:4:4:3). The objective of this study was to investigate the effects of ChondroT in collagenase-induced osteoarthritis rat model. METHODS: Osteoarthritis was induced by the injection of collagenase into the right knee joint cavity of rats. The samples were divided into seven groups [intact (n = 6), control (n = 6), indomethacin (n = 6), Joins tab (n = 6), ChondroT50 (n = 6), ChondroT100 (n = 6), and ChondroT200 (n = 6)]. The control group was administered normal saline, indomethacin group was administered indomethacin (2 mg/kg), and Joins tab group was administered Joins Tab (20 mg/kg). The ChondroT50, ChondroT100, and ChondroT200 groups were administered 50, 100, and 200 mg/kg of ChondroT, respectively. All oral administrations were initiated 7 days after the induction of arthritis and were continued for a total of 12 days. At the end of the experiment, serum aminotransferase, albumin, blood urea nitrogen, creatinine, leukocyte, and inflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6] were analyzed. Hematoxylin and eosin (H&E) and safranin O-fast green staining of the articular structures of the knee joint were performed. RESULTS: TNF-α and IL-1ß decreased in the ChondroT100 and ChondroT200 groups compared with those in the control group. IL-6 and aspartate aminotransferase decreased in the ChondroT50, ChondroT100, and ChondroT200 groups compared with that in the control group. Albumin, WBC and lymphocytes decreased in the ChondroT100 and ChondroT200 groups compared with those in the control group. In H&E stain, synoviocytes, cartilage lacunae, and chondrocytes were well preserved in the ChondroT100 and ChondroT200 groups, and safranin O-fast staining showed a clear reaction of proteoglycans in the ChondroT100 and ChondroT200 groups. CONCLUSIONS: Based on these results, it can be proposed that ChondroT has anti-osteoarthritic effects on collagenase-induced rat model.
