Anti-aging activities of Pyrus pyrifolia var culta plant callus extract

Purpose: To investigate the anti-aging properties of callus extract from Pyrus pyrifolia var. culta with skin regeneration and lightening activities.Methods: Callus extract of P. pyrifolia var. culta was produced on Murashige and Skoog (MS) medium supplemented with picloram, followed by extraction of the callus biomass in phosphate-buffered saline. The anti-oxidant activity of the extract was assessed using the DPPH free radical-scavenging assay. Inhibition of skin pigmentation by callus extract was evaluated by measuring the melanogenesis of melanoma cells. The skin-regenerating efficacy of the extract was evaluated in terms of its ability to promote procollagen synthesis and fibroblast cell proliferation.Results: The callus extract, at 10 mg/mL, exhibited 78.7 % free radical-scavenging activity, equivalent to that exhibited by 500 μM ascorbic acid. The 1 mg/mL extract solution afforded a 1.4-fold greater reduction in melanocyte melanin than did a 1 mg/mL arbutin solution. Fibroblast cells treated with 5 mg/mL callus extract exhibited 127 % higher levels of proliferation and 2.0-fold higher levels of procollagen type I C-peptide synthesis, respectively, compared with the untreated controls.Conclusion: These findings suggest that the callus extract of P. pyrifolia var. culta may be useful as a source of anti-aging cosmetic components with skin lightening and regenerating activities.Keywords: P. pyrifolia var. culta, Anti-aging, Callus extract, Skin lightening, Anti-tyrosinase activity, Melanogenesis, Wound recovery, Procollagen type I C-peptide synthesi

DPRS transformer - Dynamic pressure resistant system - Part I

In general, a transformer is designed and manufactured to operate under normal conditions. However, unexpected fault events occur due to various reasons in real-life substations. When such events do occur, an electric arc inside a transformer vaporizes the insulating oil, leading to a generation of very high expansion pressure. Once this pressure exceeds the designed threshold, the tank is then compromised, and oil starts to leak, becoming a potential cause of fire or explosion. DPRS (Dynamic Pressure Resistant System) transformer has been developed to cope with such unexpected events. In general, a PRD (Pressure Relief Device) is installed on a transformer to stabilize the pressure inside the tank. However, it requires a certain amount of time for this device to operate. DPRS transformer is designed to withstand the immediate pressure increase without severely damaging the tank (severe enough to cause an oil leak) until the PRD starts operating. Although not as much as to cause a leak, the tank will still be deformed as a result of the pressure increase. Then, insulating oil expanded by the arc is emitted safely through a designated path as the PRD starts to operate. DPRS transformer does not require additional equipment to prevent damage to the tank and is also capable of preventing fire while maintaining a similar configuration to common transformers. Due to these merits, the global demand for DPRS transformers is steadily increasing. In this article, the DPRS transformer tank design procedure and tank deformation prediction technology are presented. Additionally, a brief introduction to the explosion-proof performance verification test is addressed

Clinicopathological features of infiltrating lobular carcinomas comparing with infiltrating ductal carcinomas: a case control study

BACKGROUND: Infiltrating lobular carcinoma (ILC) is the second most common type of invasive breast cancers and it has been reported to have some unique biologic and epidemiologic characteristics. METHODS: Clinicopathological features of 95 patients with ILC, their relapse free survival (RFS) and overall survival (OS) were retrospectively investigated and compared with those of 3,621 patients with infiltrating ductal carcinoma-not otherwise specified (IDC-NOS) between January 1984 and December 2005. RESULTS: ILC constitutes 2.3% of all invasive breast cancers. There were no difference between the ILC and the IDC-NOS groups regarding age at diagnosis, tumor size, nodal status, and treatment modalities except hormone therapy. The ILC group showed more estrogen receptor expression, less HER-2 expression and higher bilaterality. RFS and OS of the ILC patients were similar to those of the IDC. IDC-NOS metastasized more frequently to the lung and bone, whereas, ILC to the bone and ovary. CONCLUSIONS: The incidence of ILC was relatively low in Korean breast cancer patients. Comparing to IDC-NOS ILC showed some different features such as higher estrogen receptor expression, less HER-2 expression, higher bilaterality and preferred metastatic sites of bone and ovary. Contralateral cancers and bone and ovary evaluation should be considered when monitoring ILC patients

Nano-mechanical behavior of ultra-stable amorphous metallic thin films

Metallic glass has amorphous structure that behave mechanically like solids but show catastrophic failure due to shear band propagation induced by short range order structure, and they are generally produced by quenching. Recently, it is observed that the slower cooling rate provides the larger time available for atoms to rearrange structure before freezing in glassy state, leading to glass transition temperature and thermal stability. These glasses with enhanced thermal stability synthesized by controlled cooling rate make it useful in various field such as mechanical or oxidation protection material. However, mechanical behavior for metallic glass with extraordinary thermodynamic and kinetic stability has not been studied. In this research, we developed a ultrastable metallic glass thin film by physical vapor deposition process at ambient temperature. Thermal stability is investigated using acceleration testing. Mechanical properties are measured using in-situ tensile testing and discuss thermal stability and fracture behavior dependent on compositio