Cre/LoxP site specific recombinase system is an effective tool for gene recombination in the body to produce specific gene deletion or inversion.The study of gene function is the experimental basis for the development of experimental animal models.Study the Cre/LoxP system,compare the different function characteristics of mouse models for Cre recombinase system in the research of ophthalmology,epecially in the tissue of retina,such as retinal pigment epithelium (RPE) cells,Müller cells and photoreceptor cells,get the Cre transgenic mouse model to establish proper experimental animal models of ophthalmology will lay a solid foundation for the research of the lack of single gene for a particular organization study.Here,the research progress of Cre/LoxP system,the Cre transgenic mouse models and eye specific Cre recombinant enzyme model mice will be summarized.

Objective To explore the ideal postoperative nursing methods of repair the lacerateon of lacrimal canaliculus. Methods Using pigtail probe to repair the lacerateon of lacrimal canaliculus in 49 patients, observed the postoperative nursing points in different clinical phases. Results There were 2 patients had the anstomotic stoma split, 1 patient had the canaliculitis. There were 46 patients had successful extubation. Conclusion The Worst lacrimal probe is an satisfactory and reliable method to repair the lacerateon of lacrimal canaliculus. The detailed interpretation and the skillful nursing care are the guarantee for successful operation.

Objective To investigate the factors affecting pulse transit time during anesthesia. Methods Sixty cases of gastrointestinal surgery under general anesthesia were investigated.The pulse transit time (PTT),BP and HR were measured at the time before and after intravenous anes-thesia induction,and at the time before and after the injection of vasoactive drugs,respectively. Results Compared to at the time before injection,HR,SBP and DBP increased significantly,and PTT decreased significantly (P <0.01 )at the time after injection of atropine and ephedrine.Com-pared to at the time before injection,HR and PTT increased significantly,while SBP and DBP de-creased significantly (P < 0.01 )at the time after injection of nicardipine.While HR and PTT de-creased significantly,and SBP,DBP increased significantly (P <0.01 )with the injection of pheny-lephrine.Obvious negative correlation between SBP and PTT was observed before and after induc-tion;meanwhile,only weak correlation between DBP and PTT was observed,and no obvious correla-tion between HR and PTT was detected.SBP and PTT were well negatively correlated with the injec-tion of atropine,ephedrine,nicardipine or phenylephrine.Conclusion All the PTT changes during anesthesia were found to be negatively correlated with the systolic blood pressure.

Objective: To observe the effect of ivabradine (IVA) on atrial and ventricular monophasic action potential duration (MAPD) and its proarrhythmic action at presence of sea anemone toxin-II (ATX-II) in isolated rabbit heart modelin vitro. Methods: The perfusion of isolated heart from female New Zealand white rabbit was conducted by Langendorff method in vitro. Left atrial and left ventricular endo- , epi-cardial action potential were recorded when pacing with ifxed frequency of 350 ms (in correspondence with the heart rate of 171 times/min) to observe the effect of IVA alone and ATX-II (3 nmol/L) with IVA on MAPD90. In addition, to observe the action of IVA alone and ATX-II with IVA on proarrhythmia when IVA reducing the heart rate to autonomous cardiac rhythm as (156±10) times/min. Results: IVA at (3-10) μmol/L prolonged atrial and ventricular endo- , epi-cardial MAPD90 by (15.9 ± 2.0) ms, (31.5 ± 4.0) ms and (23.9 ± 3.0) ms (n=6,P<0.01), respectively. ATX-II at 3 nmol/L prolonged atrial and ventricular MAPD90 by (36.5 ± 5.0)ms and (19.9 ± 3.0) ms, (19.5 ± 4.0) ms (n=6,P<0.01) respectively. With ATX-II treatment, IVA at (6-10) μmol/L decreased atrial MAPD90 by (14.4 ± 4.0) ms (n=6,P<0.01), it induced atrial arrhythmia. With 3 nmol/L of ATX-II treated ventricle, IVA at (3-10) μmol/L obviously prolonged endo- and epi-cardial MAPD90 by (36.2 ± 7.0) ms and (27.5 ± 5.0) ms(n=6,P<0.01), respectively. IVA didn’t increase ventricular beat-to-beat variability and transmural dispersion of MAPD90 no matter with or without ATX-II treatment, no ventricular arrhythmia occurred. Conclusion: IVA prolongs both atrial and ventricular MAPD, with increased late sodium current, IVA may induce atrial arrhythmia but not ventricular arrhythmia in experimental rabbits in vitro.

Objective:To explore the feasibility of bedside ultrasound in monitoring gastric residual volume and predicting feeding intolerance during enteral nutrition in critically ill patients in intensive care unit.Methods:The data of critically ill patients admitted to emergency intensive care unit of the Second Affiliated Hospital of Zhejiang University School of Medicine from April 2018 to September 2018 were retrospectively analyzed. The following patients were finally included in this study: (1) abdominal computed tomography during the stay of emergency intensive care unit was performed due to the requirement of disease evaluation and management; (2) bedside ultrasound was performed to measure the gastric antrum cross-sectional area at 30 min prior to or after abdominal computed tomography. The outline of stomach wall in the imaging of abdominal computed tomography was traced with the help of VOLUME-Work Flow medical imaging software to calculate the value of gastric residual volume. The relationship between gastric antrum cross-sectional area under semi-sitting, horizontal and right-lateral positions and gastric residual volume was evaluated by Pearson correlation analysis. The difference of gastric antrum cross-sectional area between those critically ill patients with or without feeding intolerance was compared by independent-sample t test. The predictive value of gastric antrum cross-sectional area under different body positions on feeding intolerance during enteral nutrition was analyzed by ROC curve. Results:Totally, forty-two patients were enrolled and analyzed in this study, in which the mean age was (53±13) y, mean body mass index was (21.5±2.8) kg/m 2 and mean acute physiology and chronic health evaluation was 17.0±6.9. The value of gastric residual volume was (314.5±126.6) mL, and the values of gastric antrum cross-sectional area under semi-sitting, horizontal and right-lateral positions were (7.11±4.13) cm 2, (4.22±2.66) cm 2, (8.36±4.58) cm 2, respectively. The correlation analysis indicated that gastric residual volume was positively associated with gastric antrum cross-sectional area under semi-sitting, horizontal and right-lateral positions ( r=0.543, 0.604 and 0.618, respectively; all P<0.001). During enteral nutrition, 15 patients experienced feeding intolerance while 27 patients hadn’t feeding intolerance, in which the gastric antrum cross-sectional areas under semi-sitting, horizontal and right-lateral positions were significantly increased in those patients with feeding intolerance than those patients without feeding intolerance [semi-sitting: (8.53±4.07) cm 2vs (4.60±2.76) cm 2; horizontal position: (5.15±2.75) cm 2vs (2.61±1.32) cm 2; right-lateral position: (10.32±4.06) cm 2vs (4.95±3.20) cm 2, all P<0.005] . ROC curve analysis showed that the area under ROC curves of gastric antrum cross-sectional area under semi-sitting, horizontal and right-lateral positions for predicting feeding intolerance during enteral nutrition were 0.815, 0.833 and 0.849, respectively; when its values≥3.917 cm 2, 3.395 cm 2 and 4.402 cm 2 were used as the cut-off points, the sensitivities were 92.0%, 69.6% and 92.3%, and the corresponding specificities were 69.2%, 92.3% and 71.4%, respectively. Conclusions:Bedside gastric ultrasound could accurately evaluate the status of gastric residual volume in critically ill patients, and effectively predict their occurrence of feeding intolerance during enteral nutrition.

ObjectiveTo understand the experience， knowledge and attitudes of e-cigarette users in Shanghai， and to provide evidence for the development of intervention programs for e-cigarette use. MethodsThe Respondent-Driven Sampling （RDS） method was used to recruit 40 e-cigarette users for qualitative interviews from November 2020 to February 2021. NVivo （11.0） software was used to code interview records， and the thematic pattern and relationship analysis were conducted. ResultsIn terms of the reasons and user experience of e-cigarette use， most respondents used e-cigarettes for the first time after recommendation of friends； The reasons for the current use of e-cigarettes focus on the subjective feelings generated by the use of e-cigarettes （easy to use， replacing traditional tobacco， and having many flavors）. Compared with traditional tobacco use， respondents said e-cigarettes tasted good and had no physical impact （they could be used all the time without making them uncomfortable）. In terms of the awareness of e-cigarette use related knowledge， the respondents' opinions on whether e-cigarettes caused health risks were mostly based on their own experience of using them， and they said it was difficult to identify real information online. As for whether they were interested in relevant knowledge， most respondents said they wanted to learn about the professional knowledge related to e-cigarettes. Regarding the attitude related to the use of e-cigarettes， most respondents believed that e-cigarettes are addictive， e-cigarettes are not a safe alternative to traditional tobacco， ande-cigarettes couldn't help them quit smoking. Three out of ten respondents said they supported including e-cigarettes in the Regulation on Smoking Control in Public. ConclusionThere are certain characteristics of e-cigarette users' feelings， related knowledge and attitude towards e-cigarette use that should be targeted to carry out publicity， education and intervention.

Objective:To observe the role of Huaiqihuang Granules (HQ) in the long-term management of bronchial asthma in young children, and the effective effect on concomitant rhinitis.Methods:A prospective real-world multicenter study was conducted in children aged 2-5 years with asthma diagnosed in the outpatient department (from April 2016 to March 2019)who received either inhaled corticosteroid (ICS)/leukotriene receptor antagonist (LTRA)(control group); inhaled ICS/LTRA plus HQ(combination group), or HQ alone(HQ group). All patients were followed up at week 4, 8, 12 after treatment. The number of days with asthma symptoms, the frequency of severe asthma attacks, the level of asthma control, and the days with rhinitis symptoms in the last 4 weeks were recorded. Differences before and after treatment, and those among groups after treatment were compared using Kruskal- Wallis H test or Wilcoxon rank-sum test. Results:A total of 2 234 eligible patients were recruited, and 2 147 cases completed followed-up visits, including 477, 1 374 and 296 cases in the control group, combination group, and HQ group, respectively. After the treatment, all 3 groups showed significant declines in the days with asthma symptoms, frequency of severe asthma attack and the days with rhinitis symptoms (all P<0.01), and the rate of well-controlled asthma increased significantly ( P<0.01). It lasted until the end of follow-up. Among groups, patients in the combination group showed significantly less days of asthma symptoms than those of the other 2 group at week 8 and 12[0(0, 0.9) d vs.0(0, 0.3) d, P<0.05; 0(0, 0.1) d vs. 0(0, 1.0) d, P<0.01]. Patients in the combination group and HQ group showed a significantly lower rate of severe asthma attacks than that of the control group at week 12 [0(0, 1), 0(0, 1), 0(0, 2), all P<0.05]. The well-controlled rate of asthma in the combination group was significantly higher than that of the control group and HQ group at week 8 and 12 (89.6% vs. 85.9% vs.82.1%, H=15.28; 90.9% vs. 84.1% vs. 81.8%, χ2=29.32, all P<0.01). Conclusions:HQ can significantly alleviate symptoms of asthma and rhinitis, severe attack of asthma, and increase the control rate of asthma when used as an additional treatment or used alone.