电化学聚合法制备分子印迹电极用于饮料中兴奋剂的检测——对“电聚合制备导电高分子”实验的改进

以大学化学实验中“电聚合制备导电高分子”为基础,融入分子印迹聚合物与食品安全元素,成功将简单的任务式制备实验,改进为集分子印迹导电聚合物制备、性能表征及饮料中兴奋剂的高选择性检测应用为一体的综合性实验。改进后实验内容丰富有趣,贴近现实,引入前沿分析技术,有助于学生综合技能的提升和科学思维的培养。

Rapid method for on-site determination of phenolic contaminants in water using a disposable biosensor

A disposable biosensor was fabricated using single-walled carbon nanotubes, gold nanoparticles and tyrosinase （SWCNTs-AuNPs-Tyr） modified screen-printed electrodes. The prepared biosensor was applied to the rapid determination of phenolic contaminants within 15 minutes. The SWCNTs-AuNPs-Tyr bionanocomposite sensing layer was characterized with scanning electron micro- scopy, electrochemical impedance spectroscopy and cyclic voltammetry methods. The characterization results revealed that SWCNTs could lead to a high loading of tyrosinase （Tyr） with the large surface area and the porous morphology, while AuNPs could retain the bioactivity of Tyr and enhance the sensitivity. The detection conditions, including working potential, pH of supporting electrolyte and the amount of Tyr were optimumed. As an example, the biosensor for catechol determination displayed a linear range of 8.0 × 10^-8 to 2.0 × 10^- 5 mol.L-1 with a detection limit of 4.5 × 10^-8 mol.L-1 （S/N= 3）. This method has a rapid response time within 10 s, and shows excellent repeatability and stability. Moreover, the resulting biosen- sor could be disposable, low-cost, reliable and easy to carry. This kind of new Tyr biosensor provides great potential for rapid, on-site and cost-effective analysis of phenolic contaminants in environmental water samples.

Clinical features and outcome of 15 patients with recurrent endometrial cancer or atypical endometrial hyperplasia received primary fertility-sparing therapy followed by hysterectomy

Objective To investigate the clinical features and outcome of recurrent endometrial cancer(EC)or atypical endometrial hyperplasia(AEH)patients who underwent hysterectomy after fertility-sparing therapy.Methods Clinical data was retrospectively collected for 15 recurrent endometrial cancer or atypical endometrial hyperplasia patients who underwent hysterectomy in six hospitals from 2003 to 2019.According to the indicators of hysterectomy,patients were divided into four groups:7 patients who underwent direct hyesterectomy after the first relapse,4 due to re-treatment failure,1 after full term live birth,and 3 because of multiple recurrence.Clinical coexisting conditions,regimen and outcome of fertility-sparing therapy,pre-and post-operative pathological results,and prognosis were analyzed.Results(1)Fertility-spraring treatment was given to a total of 15 eligible patients,including 6 with EC and 9 with AEH.Median time interval from remission to recurrence was 12 months(range 3–92).Oral progestin-based medicine was the main fertility-sparing therapy in both primary treatment and re-treatment after recurrence.Six(6/8)patients received progestin combined with gonadotrophin releasing hormone agonist or metformin in three re-treatment groups.(2)Nine patients underwent hysterectomy and 6 staging surgery.Three patients had pathological upgrade after surgery.Five(5/10)EC patients had superficial myometrial invasion in postoperative pathology.All patients showed no evidence of disease in the median follow-up of 17 months(range 3–118).(3)Among seven patients who failed to re-treatment and had multiple recurrence,six were overweight/obesity and six had insulin resistance.Two of these patients had synchronous ovarian cancer in the postoperative pathology.Conclusion For the patients with recurrent EC or AEH after primary fertility-sparing therapy,overweight/obesity and insulin resistance might be the risk factors for re-treatment failure.Hysterectomy is recommended when patients had re-treatment failure or multiple recurrence;and generally the prognosis is favorable.

Toxicity effects of disinfection byproduct chloroacetic acid to Microcystis aeruginosa: Cytotoxicity and mechanisms

Chlorine-based disinfectants are widely used for disinfection in wastewater treatment.The mechanism of the effects of chlorinated disinfection by-products on cyanobacteria was unclear.Herein,the physiological effects of chloroacetic acid(CAA)on Microcystis aeruginosa(M.aeruginosa),including acute toxicity,oxidative stress,apoptosis,production of microcystin-LR(MC-LR),and the microcystin transportation-related gene mcyH transcript abundance have been investigated.CAA exposure resulted in a significant change in the cell ultrastructure,including thylakoid damage,disappearance of nucleoid,production of gas vacuoles,increase in starch granule,accumulation of lipid droplets,and disruption of cytoplasm membranes.Meanwhile,the apoptosis rate of M.aeruginosa increased with CAA concentration.The production of MC-LR was affected by CAA,and the transcript abundance of mcyH decreased.Our results suggested that CAA poses acute toxicity to M.aeruginosa,and it could cause oxidative damage,stimulate MC-LR production,and damage cell ultrastructure.This study may provide information about the minimum concentration of CAA in the water environment,which is safe for aquatic organisms,especially during the global coronavirus disease 2019 pandemic period.

NPY Genes Play an Essential Role in Root Gravitropic Responses in Arabidopsis

Plants can sense the direction of gravity and orient their growth to ensure that roots are anchored in soil and that shoots grow upward. Gravitropism has been studied extensively using Arabidopsis genetics, but the exact mecha- nisms for gravitropism are not fully understood. Here, we demonstrate that five NPY genes play a key role in Arabidopsis root gravitropism. NPYgenes were previously identified as regulators of auxin-mediated organogenesis in a genetic pathway with the AGC kinases PID, PID2, WAG1, and WAG2. We show that all five NPYgenes are highly expressed in primary root tips. The single npy mutants do not display obvious gravitropism defects, but the npyl npy2 npy3 npy4 npy5 quin- tuple mutants show dramatic gravitropic phenotypes. Systematic analysis of all the npy double, triple, and quadruple combinations demonstrates that the five NPY genes all contribute to gravitropism. Our work indicates that gravitropism, phototropism, and organogenesis use analogous mechanisms in which at least one AGC kinase, one NPH3/NPY gene, and one ARF are required.

Comparison of dynamic defocus curve Checkfor updates on cataract patients implanting extended depth of focus and monofocal intraocular

Background:The aim of the study was to compare the dynamic defocus curve on patients post-implantation of the extended depth-of-focus(EDOF)and monofocal intraocular lens(IOL).Methods:A total of 62 age-related cataract patients receiving phacoemulsification with implantation of TECNIS Symfony(ZXRoO)or monofocal IOLs were enrolled.The binocular static and dynamic defocus curves with corrected distance visual acuity were evaluated at one month postoperatively.Results:The ZXR00 group achieved signifcantly better intermediate(P=0.044)and near(P=0.017)visual acuity(VA)than the monofocal group.Two groups had similar uncorrected and corrected distance VA(P>0.05,respectively).The dynamic defocus curve revealed a smoother decline from 0.0 D to-2.0 D in the ZXRo0 group.Defocused dynamic VA in the ZXR00 group was significantly better(P<0.05)except at 0.0 D(P=0.724)and-0.5 D(P=0.176).The area under the curve(P=0.002)and corrected dynamic vision accommodation(P=0.001)derived from the dynamic defocus curves were better in the ZxRoo group.A positive correlation was observed between defocused dynamic and static VA in both groups(P<0.001).Multiple linear regression analysis indicated that defocused static VA and cor-rected dynamic vision accommodation were significant influential factors for the defocused dynamic VA from-1.0 D to-3.0 D(P<0.05).Conclusions:The EDOF IOL provided similar distant vision,better intermediate and near vision,and a better overall dynamic defocus curve than the monofocal IOL.The dynamic defocus curve may be comprehensively applied to evaluate the all-distance dynamic visual performance post-cataract surgery.