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It is hard for traditional current protection to solve problems of distribution networks with highly penetrative DGs. The fault information required by the most protection methods cannot be provided by the poor infrastructure of distribution networks. In this paper, a sufficient criterion based on the maximal current differences between adjacent transmission lines is proposed to promote selective configuration of protection scheme. The principle of the criterion and its advantages on current protection application are analyzed. The suppress influence of DG on the current of downstream transmission line current can be processed without high demand for communication in distribution network with DGs. Through the simulation in Matlab/Simulink, the effectiveness of the proposed criterion is validated.

Ethnopharmacological relevance A fruit of Ginkgo biloba L. also known as Ginkgo biloba , can be used for the treatment of cancer in Chinese traditional medicine. The scientific name of succulent skin, which is the episperm of Ginkgo nuts, is exocarp. Experiment shows that Ginkgo biloba exocarp extracts (GBEE) has the effects of immune promotion, cancer inhibition and etc. Aim of study Study on the activity of GBEE against Lewis lung cancer (LLC) angiogenesis and its partial molecular mechanism. Materials and methods The effect of GBEE on proliferation of LLC cells was detected by MTT method in vitro. The metastasis model of LLC was set up. The C57BL/6J mice were randomly separated into normal control, model control, positive control and GBEE (50, 100, 200 mg/kg) treatment groups, n=10. The mice in normal group and model group were both intragastric gavage (i.g.) normal saline (NS) in a volume of 0.1 mL/10 g (b.w.), positive group were intraperitoneal (i.p.) injection cyclophosphamide (CPA) at a dose of 20 mg/kg (b.w.) , the GBEE treatment groups were respectively i.g. GBEE 50, 100, and 200 mg/kg (b.w.), once a day for 20 d. After treatment, we calculated the tumor inhibition rate and anti-metastasis rate. The microvessel density (MVD) was measured by immunohistochemistry method in transplanted tumor. The expression levels of vascular en-dothelial growth factor (VEGF) and VEGFR2 mRNA or Wnt3a, β-catenin, VEGF, VEGFR2 and p-Akt/Akt protein expression were respectively tested by Quantitative Reverse transcription Polymerase chain reaction (qRT-PCR) or western blot in vitro and vivo. Results GBEE suppressed the growth of LLC cells in a dose-dependent way at the dose of 5, 10, 20, 40, 80 and 160 µg/mL in vitro. It can suppressed Wnt3a and β-catenin protein expression and the content of mRNA of VEGF and VEGFR2 in LLC cells significantly. In vivo, we discovered GBEE can retard the growth of LLC transplanted tumor in a dose-dependent way at the dose of 50, 100, 200 mg/kg, suppressing tumor lung metastasis. The expression of CD34 was reduced, which means MVD was inhibited and so do β-catenin, VEGF, VEGFR2 and p-AKT/AKT protein expression and VEGF and VEGFR2 mRNA expression levels in LLC transplanted tumor of C57BL/6 mice. Conclusions GBEE played the effects of anti-tumor and anti-metastatic depending upon the inhibition of tumor angiogenesis, which may be closely relevant to its effect in blockage of Wnt /β-catenin-VEGF signaling pathway in LLC.