Molecularly imprinted polymers (MIPs) with high selectivity to tilmicosin (TIM) were prepared using tylosin(TYL) as dummy template, methacrylic acid(MAA) as monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker.The effects of 4 porogens including dimethyl formamide, methanol, acetone, and chloroform on the recognition capability of MIPs were investigated.Orthogonal test was used to optimize the preparation of MIPs, and the optimal composition was as follows; 1.0 mmol TYL, 8.0 mmol MAA, 20.0 mmol EGDMA, 6.0 mL chloroform, 20.0 mg azobisisobutyronitrile.The solid phase extraction condi tions and characteristics of MIPs as adsorptive material for the selective extraction and enrichment of TIM were also studied.The recovery of TIM was above 90% when the following procedure was applied to MIPs cartridge: conditioning with methanol and water(pH 9.0), loading with acetonitrile, cleaning with methanol and chloroform respectively, and eluting with 3 mL methanol-ammonia(95:5, V/V).The recovery of TIM on non-imprinted polymers cartridge was only 32%.

Objective:To explore the protective effect of thioether-cyclized helix B peptide (CHBP)on renal tubular epithelial cells and its mechanism by experiment in vitro.Methods:Human renal proximal tubular epithelial cell line HK-2 cells were cul-tured in vitro and divided into control group,H2 O2 group and CHBP group.Oxidative stress damage models were established by stimulation with 500 μmol/L H2 O2 for 4 h.In CHBP group,20 nmol/L CHBP was added to the culture medium 1 h prior to the establishment of oxidative stress model.After 4 h stimulation with 500 μmol/L H2 O2 ,cell viability,situation of apopto-sis,and severity of oxidative stress damage were measured.The expressions of Binding immunoglobulin protein(BiP),C/EBP homologous protein(CHOP),and the molecular in downstream NF-E2-related factor 2 (Nrf2)signaling pathway were detected by Western blotting and real-time PCR analysis,so as to evaluate the level of endoplasmic reticulum(ER)stress.Results:Oxi-dative stress induced cytotoxic injury could be alleviated by CHBP pretreatment.Kit-8 (CCK-8 )assay and TUNEL showed that,after CHBP pretreatment,cell viability increased,while cell apoptosis,oxidative stress and ER stress decreased.The levels of Nrf2 and heme oxygenase-1(HO-1)were significantly higher in CHBP group than those in H2 O2 group.Conclusions:CHBP pretreatment could alleviate oxidative stress damage of HK-2 cells,and the protective effect may be achieved by inhibi-ting ER stress and activating downstream Nrf2 signaling pathway.

The gradual acceleration of the aging population in China has led to an increased demand for mobility aids,and the reliability of domestic wheeled walking-aid is one of their important attributes,but there is little research on the reliability of mobility aids.This paper conducts the failure mode,effects and criticality analysis on domestic wheeled walking-aid.By collecting,collating and analyzing the 26 failure modes,the key modules are the chassis and the lifting system.The key modules are obtained,and the failure data is analyzed to find out that the lifetime distribution model is log-normal and the 0.95 lower confidence limit for reliability life of product t0.9 is 2489.4 hours.The study aims to provide ideas for the reliability analysis of other active medical devices and calls for the formation of a reliability study review point for the industry that meets the requirements of Chinese medical device regulations.

Active medical device is a kind of medical device which is widely used. In order to realize the goal of high-quality development, product with high reliability is a necessary requirement for the domestic active medical device industry. By means of literature research, data collection, field research, materials comprehensive combing and analysis, this paper systematically analyzes and studies the current situations and the existing problems of reliability and evaluation from the dimensions of Chinese active medical device industry policy, enterprise situation and evaluation method. In addition, by considering the technical characteristics of reliability work, concrete suggestions for solving the problems are given from the directions of standard and guiding principle, so as to provide reference for active medical device industry to develop scientific and objective reliability technical standard system and guiding principle, which are in accord with the current characteristics of Chinese active medical device industry and supervision.
Reproducibility of Results ; Industry ; China