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Background and Aims. To investigate the clinical effect of preservation or nonpreservation of the left colic artery (LCA) in total mesorectal excision (TME) under laparoscopy. Methods. The words, like "rectal cancer," "left colonic artery," and "laparoscopy," were used as the retrieval terms, and the keyword retrieval method was adopted. The retrieval period was set as from January 1, 2013, to June 1, 2018. We searched databases including PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) to collect randomized and controlled trials which compared the effect of preservation or nonpreservation of the LCA in TME under laparoscopy. Two researchers independently carried out literature screening, data extraction, and literature quality evaluation; Review Manager 5.3 was used for the meta-analysis. Results. Seven studies including 1467 cases were identified for the meta-analysis. As showed by the meta-analysis, compared with the LCA nonpreservation group, the LCA preservation group had significantly reduced incidence of anastomotic leakage (OR = 0.44 , CI = 0.30 , 0.65 , P < 0.0001) and postoperative urinary and sexual dysfunction (OR = 0.26 , CI = 0.09 , 0.78 , P = 0.02) and significantly shorter time for intestinal function recovery (WMD = − 0.26 , CI = − 0.41 , − 0.11 , P = 0.0008). There were no significant differences between the two groups in the duration of surgery, blood loss, number of dissected lymph nodes, or postoperative hospital stay. Conclusions. From the results, the LCA preservation group seems to achieve comparable success with acceptable safety outcomes. Therefore, this surgical method can be recommended in the clinical practice. [ABSTRACT FROM AUTHOR]

Frequency domain spectroscopy (FDS) is employed to evaluate the moisture content and aging state of oil-paper insulation in power transformers. Oil-paper insulation samples with different moisture content and aging states were primarily prepared in the laboratory. A method was proposed based on a study of the influence of the aging state and moisture content on the frequency domain dielectric property of oil-paper insulation. This method distinguishes the influence of moisture content and aging state on FDS through the imaginary part of complex relative permittivity ( εr″). Relevant characteristic parameters that characterize the moisture content and aging state of oil-impregnated pressboards were also extracted. Results reveal that the extracted characteristic parameters are sensitive to moisture content in the range of 10−1 Hz to 101 Hz and in the range of 10−3 Hz to 10−1 Hz for the aging state. An obvious exponential relationship exists between the maximum values of the characteristic parameters in the given frequency ranges and degree of polymerization and moisture content. The new method can be utilized for a non-destructive condition assessment of oil-paper insulation of transformers. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]