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To assess if experimental warming interventions are superior to routine warming interventions in preventing perioperative hypothermia.Perioperative hypothermia is a critical issue for the complications of surgery. There are various kinds of perioperative warming interventions, including experimental and routine warming interventions.We performed a systematic literature review and meta-analysis for the randomized clinical trials of experimental warming interventions vs. routine warming interventions in the perioperative period.A total of 15 studies were included with 983 participants allocated to experimental warming interventions and 939 controls with routine warming interventions, who were receiving a variety of surgeries. The focused outcome was the intraoperative and postoperative body temperature. All included studies were randomized clinical trials. Among the participants receiving operations, the meta-analysis showed that routine warming intervention groups experienced lower intraoperative and postoperative body temperatures compared to the experimental warming groups. The meta-analysis results included positive mean differences, significant tests for overall effect and significant heterogeneity in the random-effects model.In spite of significant heterogeneity, experimental warming interventions are likely to demonstrate superior warming effects when compared to routine warming interventions, as shown by the current meta-analysis results of randomized clinical trials.

In order to meet the damper performance requirements of heavy vehicles, a stepped-bypass magnetorheological damper is proposed. The mathematical model of damping force is deduced, and its mechanical properties are numerically simulated. Then the damper is manufactured, and the mechanical properties of the stepped bypass magnetorheological damper are experimentally studied. The simulation are consistent with the experimental results. The damper is optimized by orthogonal optimization design test. Finally, it is concluded that the maximum output damping force of the stepped bypass magnetorheological damper is about 4500 N, and the adjustable coefficient K is about 5.4. After optimization, the damping force of the stepped bypass magnetorheological damper is increased by at least 5.3%, and the adjustable coefficient K is at least 1.37 times that before optimization, which is 13% wider than that before optimization.

Background Accumulating evidence indicates that circular RNAs (circRNAs) act as microRNA (miRNA) sponges to directly inhibit specific miRNAs and alter their ability to regulate gene expression at the post-transcriptional level; this mechanism is believed to occur in various cancers. However, the expression level, precise function and mechanism of circ_001680 in colorectal carcinoma (CRC) are largely unknown. Methods qRT-PCR was used to detect the expression of circ_001680 and miR-340 in human CRC tissues and their matched normal tissues. Bioinformatics analyses and dual-fluorescence reporter assays were used to evaluate whether circ_001680 could bind to miR-340. Circ_001680 overexpression and knockdown cell lines were constructed to investigate the proliferation and migration abilities in vivo and in vitro through function-based experiments, including CCK8, plate clone formation, transwell, and wounding healing assays. The relationships among circ_001680, miR-340 and BMI1 were investigated by bioinformatics analyses, dual-fluorescence reporter system, FISH, RIP and RNA pull down assays. Sphere forming assays and flow cytometry analyses were used to assess the effect of circ_001680 on the stemness characteristics of CRC cells. Results Circ_001680 was more highly expressed in of CRC tissue than in matched adjacent normal tissues from the same patients. Circ_001680 was observed to enhance the proliferation and migration capacity of CRC cells. Furthermore, dual-fluorescence reporter assays confirmed that circ_001680 affects the expression of BMI1 by targeting miR-340. More importantly, we also found that circ_001680 could promote the cancer stem cell (CSC) population in CRC and induce irinotecan therapeutic resistance by regulating the miR-340 target gene BMI1. Conclusions Our results demonstrated that circ_001680 is a part of a novel strategy to induce chemotherapy resistance in CRC through BMI1 upregulation. Moreover, circ_001680 may be a promising diagnostic and prognostic marker to determine the success of irinotecan-based chemotherapy.

Additional file 5: Figure S4. Irinotecan resistance induced by different concentration gradients of BMI1 in CRC cells. (A) SW480 cells were transiently transfected with the indicated amounts of BMI1. The protein level of BMI1 was detected by Western blotting after 48 h. (B) Representative growth of the indicated cells as determined by a CCK8 assay. (C) The number of subpopulation cells with the CD44+/CD133+ phenotype in the indicated SW480 cells (left). Quantification of cells with the CD44+/CD133+ phenotype is shown in the histogram (right). (D) Apoptosis assay of the indicated cells by flow cytometry (left). Statistical analysis of the flow cytometry results (right). (E) Typical images from the sphere formation assay of the indicated lentivirus-infected cells treated with or without irinotecan. The error bars represent the mean ± SD from three independent experiments. **p

Additional file 3: Figure S2. Circ_001680 affected the growth ability of CRC in vitro. (A) Representative transwell images of the effect of circ_001680 on the migration of the indicated cells (left). Statistical analysis of the transwell assay results (right). (B) The wound healing assay results showing divergent migration capacities at 4 regular intervals in the indicated cells (left); the statistical analysis is shown on the right. The error bars represent the means ± SDs from three independent experiments. *p

Background Aberrant activation of Wnt/β-catenin signaling pathway is considered to be an important issue in progression and metastasis of various human cancers, especially in colorectal cancer (CRC). MiR-452 could activate of Wnt/β-catenin signaling. But the mechanism remains unclear. Methods The expression of miR-452 in CRC and normal tissues was detected by real-time quantitative PCR. The effect of miR-452 on CRC growth and invasion was conducted by functional experiments in vitro and in vivo. Bioinformatics and cell luciferase function studies verified the direct regulation of miR-452 on the 3’-UTR of the GSK3β, which leads to the activation of Wnt/β-catenin signaling. Results MiR-452 was upregulated in CRC compared with normal tissues and was correlated with clinical significance. The luciferase reporter system studies affirmed the direct regulation of miR-452 on the 3’-UTR of the GSK3β, which activate the Wnt/β-catenin signaling. The ectopic upregulation of miR-452 significantly inhibited the expression of GSK3β and enhanced CRC proliferation and invasion in vitro and in vivo. Meanwhile, knockdown of miR-452 significantly recovered the expression of GSK3β and attenuated Wnt/β-catenin-mediated cell metastasis and proliferation. More important, T-cell factor/lymphoid enhancer factor (TCF/LEF) family of transcription factors, which are crucial downstream molecules of the Wnt/β-catenin signaling pathway was verified as a valid transcription factor of miR-452’s promoter. Conclusions Our findings first demonstrate that miR-452-GSK3β-LEF1/TCF4 positive feedback loop induce CRC proliferation and migration.