A novel electrochemical method based on dehydroabietylamine schiff base( DBS) and multi-walled carbon nano-tubes( MWCNTs) composite modified glassy carbon electrode was presented for determination of Pb2+. The electrochemical behaviors of Pb2+on the modifled electrode were investigated by cyclic voltammetry ( CV) and differential pulse anodic stripping voltammetry ( DPASV ) . The results showed that under the optimized conditions including 0 . 2 mol/L NaAc-HAc used as supporting buffer ( pH 5 . 5 ) , -1 . 1 V of accumulating potential, 250 s of accumulating time, the oxidation peak current was proportional to Pb2+concentration in the range between 1 × 10-8 mol/L and 1 × 10-6 mol/L with the linear regression equation as I(μA)= 6. 6173c(μmol/L)+0. 2597(R=0. 9971) and the detection limit as 5. 0×10-9 mol/L (S/N=3). The proposed sensor was successfully employed to determine Pb2+ in real samples with satisfactory results. In addition, this method showed the advantages of simple operation, short assay time, good accuracy, satisfactory efficiency and good selectivity for determination of low concentration lead in water samples.

Objective To investigate the effect of autophagy in radiosensitivity of nasopharyngeal carcinoma CNE-2 cells.Methods The expression of ATG5 in CNE-2 cells was inhibited by lentiviral mediated RNA interference.The cells were divided into three groups:control group,NC group and ATG5 group.Cell proliferation,apoptosis and radiosensitivity were detected by CCK-8 method,flow cytometry and colony-forming assay,respectively.Results Compared with the NC group and control group,the survival of ATG5-interfected cells was reduced (F =3.755,46.086,8.609,44.160,P ＜ 0.05).After 6 Gy X-ray irradiation,the apoptosis index of the ATG5 group significantly higher than that of NC group and control group (F =394.876,P ＜ 0.05).In addition,the radiosensitivity of ATG5 group was also higher than that of control cells.Conclusions Suppression of autophagy activity enhances the radiosensitivity of human nasopharyngeal carcinoma cells.

Objective To understand the status of resistance to multiple insecticides and the frequencies of kdr mutations in Culex pipiens pallens from north?central Anhui Province. Methods From July to September,2014,the C. pipiens pallens mosquito larvae were collected in Huaibei,Bengbu and Chuzhou cities of the north?central Anhui Province and reared to adults. The female adult mosquitoes at 3-5 days post emergence were tested for susceptibility to the four insecticides,namely 0.05%deltamethrin,5%malathion,0.1%bendiocarb and 4%DDT,by using the standard WHO resistance tube bioassay. The detec?tion of the point mutations of the kdr gene at codon 1014 was conducted by PCR and DNA sequencing in the deltamethrin?resis?tant and?susceptible mosquitoes. Results High levels of resistance to all the four insecticides were found in all the three tested populations,although mosquito mortality varied among populations and test insecticides. Among the test insecticides,DDT showed lowest mortality with no significant difference(F=1.027,P>0.05)in all test populations,whereas significantly differ?ent mortalities were observed among populations for the remained three insecticides tested(deltamethrin,malathion,and ben?diocarb)(F = 23.823,33.955,128.841;all P < 0.01). Two types of non?synonymous kdr mutation at codon position 1014 (L1014F and L1014S)were observed. A positive correlation between L1014F mutation frequencies and deltamethrin resistance levels were detected in the three mosquito populations(r2=0.718,P<0.01). Conclusions The observed high levels of resis?tance to multiple?insecticides coupled with the occurrence of medium to high kdr frequencies in populations of C. pipiens pallens could profoundly affect the mosquito vector control programme in China. The local health departments need to strengthen vector dynamic monitoring and implement rational resistance management strategies.

Objective To investigate the effect of Amp activated protein kinase(AMPK)activity in radiosensitivity of human na-sopharyngeal carcinoma cells .Methods Human nasopharyngeal carcinoma cells ,CNE-2 ,were treated with AMPK inhibitor ,Com-pound C(CC) ,for 1 h .Then cells were explored in X-ray .The expression of total AMPK (t-AMPK) ,phosphorylation AMPK (p-AMPK) ,and MAPlLC3 were detected by Western blot .The number of autophagosomes were observed and calculated by transmis-sion electron microscope(TEM) .Cells processed with CC were explored in X-ray .MTT assay was used to detect the difference of two groups in cell proliferation .Cell apoptosis were assayed by flow cytometry .Results The expression of p-AMPK in CC group cells were significantly downregulated compared to the negative control group cells (P< 0 .01) ,while no significant change of t-AMPK expression were found(P>0 .05) .The expression of MAPlLC3 and the number of autophagosomes in CC group cells were significantly decreased compared to the control group cells (P<0 .05) .Correspondingly ,the cell proliferation rate in CC group was lower than in control group ,and the percent of apoptosis cells was higher in CC group than in control group (P<0 .05) .Conclusion Suppression of AM PK activity could inhibited autophagy induced by decreasing the degree of p-AM PK ,then enhanced the effect of proliferation inhibition and apoptosis promotion in CNE-2 cells .The AMPK inhibitor ,CC ,can serve as an effective assistant treatment of radiotherapy for nasopharyngeal carcinoma .

Objective To study the effect of exogenous nitric oxide donor sodium nitroprusside(SNP)on antioxidant en?zymes activities and lipid peroxidation of mice infected with Trichinella spiralis. Methods BALB/c mice were infected with T. spiralis separated by the digestion method. Forty?two days post?infection,the peripheral blood and hepatic tissue from the in?fected or normal mice were collected. Then 4 groups were set:liver homogenate from infected mice+SNP(Group A),liver ho?mogenate from normal mice+SNP(Group B),peripheral blood from infected mice+SNP(Group C),and peripheral blood from normal mice+SNP(Group D). The final concentrations of SNP in each group were set as 0(blank control),2,5,10μmol/L and 30μmol/L,respectively. After reacting with SNP at 37℃for 30 min,the superoxide dismutase(SOD),glutathi?one peroxidase(GSH?Px),catalase(CAT)activities,and malondialdehyde(MDA)concentration were examined and com?pared. Results The levels of SOD,CAT,GSH?Px and MDA concentration in the liver and the blood from the mice infected with T. spiralis were significantly higher than those of the normal ones(all P < 0.05). When reacted with 10 μmol/L and 30 μmol/L SNP,the SOD,GSH?Px,and CAT activities in Group A and B decreased significantly(all P<0.05),while the liver MDA concentration reacted with 2-30μmol/L SNP increased obviously(all P<0.05). As reacted with 30μmol/L SNP,the ac?tivities of blood SOD,GSH?Px,and CAT in Group C and D decreased,while the MDA concentration in blood still increased (all P<0.01). When the SNP concentration was in the range of 2-30μmol/L,there were a negative correlation between the SNP concentrations and SOD,GSH?Px,and CAT activities,as well as a positive correlation with the MDA concentration in the liver and blood from the mice infected with T. spiralis(all P<0.05). Conclusions T. spiralis infection could cause oxidative damage to mice,and increase SOD,GSH?Px,and CAT activities. Nitric oxide released from SNP can decrease antioxidase activ?ities,and inhibit the antioxidant capacity of mice infected with T. spiralis.

Objective To explore the anti-tumor effect of 17XL strains of Plasmodium yoelii(P.y)infection on melanoma in mice. Methods B16F10 tumor cells were axillarilly injected into the right flank of 20 C57BL/6 mice to establish tumor-bearing mouse models. The next day,the mice were randomly divided into a P.y infection group and control group,10 mice each group. Each mouse of the P.y infection group was intraperitoneally injected with 1×106 red blood cells including 20% P.y infection red blood cells,and each one of the control group were intraperitoneally injected with 1×106 normal red blood cells of C57BL/6 mice. The time of tumor formation of the mice in the two groups was observed and the tumor volumes were measured. Results The time of tumor formation in the P.y infection group[(11.30 ± 0.21)d]was significantly later than that in the control group [(10.40 ± 0.22)d](P < 0.05). From the tumors could be accurately measured to the study end point,both the tumors of mice in the two groups were growing,and the tumor volumes of mice in the P.y infection group were significantly less than those in the control group at each time point(all P < 0.05). The growth rate of tumors in the P.y infection group[(71.10 ± 6.29)mm3/d]was significantly slower than that in the control group[(302.80 ± 49.94)mm3/d](P < 0.05),and the growth rates of tumors every day in the P.y infection group were significantly slower than those in the control group(all P < 0.05). Conclusion The P.y in-fection can delay the occurrence of tumor and inhibit the growth of melanoma.

Teaching competition is an effective way for college and university teachers to improve their teaching skills. Based on the teaching practice and experience in medical parasitology,this paper discusses several key issues in teaching competition including topics,teaching designs and teaching methods. It provides references for the teachers in department of parasitology of universities and colleges to improve the quality of classroom teaching.

Objective To investigate the risk factors for secondary infection in patients with acute ischemic stroke(AIS)undergoing intravenous thrombolysis,and to construct a nomogram model.Methods A retrospective analysis was performed for the clinical data of 391 patients with AIS who underwent intravenous thrombolysis in Nanjing Drum Tower Hospital retrospectively from December 2016 to December 2021,and according to the presence of absence of secondary in-fection,they were divided into infection group with 75 patients and non-infection group with 316 patients.Results Age[odds ratio(OR)=1.049,95%confidence interval(CI)1.017-1.082],history of renal insufficiency(OR=3.76,95%CI 1.382-9.966),history of antihypertensive drugs(OR=0.298,95%CI 0.144-0.562),hemorrhagic transforma-tion after thrombolysis(OR=2.851,95%CI 1.05-7.36),white blood cell count(WBC)on admission(OR=1.17,95%CI 1.045-1.313),prothrombin time(PT)on admission(OR=1.585,95%CI 1.206-2.167),and dysphagia(OR=8.309,95%CI 4.091-17.269)were independent risk factors for secondary infection.The nomogram predictive model based on these risk factors had an area under the ROC curve of 0.867 and a cutoff value of 0.180,suggesting that the model had good discriminatory ability and calibration.According to the cutoff value of the nomogram,the patients were di-vided into high-risk and low-risk groups based on the risk of secondary infection,and the low-risk group had a significantly higher cumulative survival rate than the high-risk group(P<0.000 1).Conclusion Age,history of renal insufficiency,his-tory of antihypertensive drugs,hemorrhagic transformation after thrombolysis,WBC on admission,PT on admission,and dysphagia on admission are risk factors for secondary infection in AIS patients after intravenous thrombolysis,and the nomo-gram predictive model constructed based on the above risk factors has a good value in predicting secondary infection and 90-day survival.

Objective:To explore the effectiveness and safety of holmium laser treatment via flexible bronchoscopy in children with tracheobronchial tuberculosis (TBTB).Methods:The clinical data of 40 children with TBTB admitted in Qilu Children′s Hospital of Shandong University from February 2016 to June 2019 were retrospectively analyzed. According to the treatment approach, they were divided into conventional treatment group (20 cases) and holmium laser treatment group (20 cases). The sex, age, course of disease and lesion location before treatment, and the time till relief of atelectasis and airway obstruction after treatment were compared between the two groups with t test and χ 2 test. Results:Among the 40 cases, 24 were males and 16 females, and 35 had lymph node fistula (87.5%) and 5 had granulation proliferation (12.5%). There was no statistically significamt difference between the conventional group and laser group in sex (male ratio: 50%（10/20） vs. 75%（15/20）, χ 2=2.66, P=0.10), age （(3.2±2.2） years vs. （2.2±1.8） years, t=1.41, P=0.16), course of disease (<1 month ratio: 30%（6/20） vs. 35%（7/20）, χ 2=0.11, P=0.73), lesion location (single lesion ratio： 45%（9/20） vs. 60%(12/20), χ 2=0.90, P=0.34). The effectiveness was evaluated after 3 months, and the total effective rate were 100% in laser group and 40% in conventional group, the difference was significant (χ2=25.34, P<0.01). No serious adverse events occurred in the two groups during the observational period. Conclusions:Holmium laser treatment via bronchoscopy is an effective way to remove the tuberculosis foci in the trachea, which can reduce the incidence of further related complications, and could be applied in clinical approach.

Objective To explore the evolvement rule of TCM syndrome types of the transformation of chronic gastritis (CG):from chronic non-atrophic gastritis (CNAG),chronic atrophic gastritis (CAG) to precancerous lesions of gastric carcinoma (PLGC).Methods Based on gastroscopy and gastrobiop-sy,altogether 592 patients included from three hospitals affiliated to Beijing University of Chinese Medi-cine Dongzhimen Hospital,(Dongfang Hospital and Third affiliated Hospital)and Wangjing hospital of China Academy of Chinese Medical Sciences from September 2013 to February 2014,were diagnosed with CNAG (338 cases),CAG (134 cases)and PLGC (120 cases).By using Epidata 3.1 the database was established,then principal component analysis,factor analysis and Chi-square test were conducted by using software SPSS 17.0.Results There were nine common syndrome types in CNAG,and the three leading ones were syndrome of incoordination between spleen and stomach,syndrome of heat-stag-nation in liver and stomach,syndrome of incoordination between liver and stomach.There were ten syn-drome types in CAG,and the highest frequency was syndrome of incoordination between liver and stom-ach,then syndrome of static blood in stomach collaterals and syndrome of deficient cold of spleen and stomach.The highest frequency of three syndrome of ten in PLGC were syndrome of yin deficiency in stomach,syndrome of yang deficiency in stomach and syndrome of static blood in stomach collaterals. The frequencies of location factors of CNAG from high to low were stomach,liver and spleen,the same as those of CAG;the frequencies of nature factors from high to low were qi stagnation,heat,qi deficiency, dampness and yang deficiency,which were some different from those of CAG being qi stagnation,heat, yang deficiency,dampness,blood stasis,yin deficiency and qi deficiency.With the disease progression, the frequencies of location factors of PLGC from high to low were stomach,spleen and liver,while those of nature factors were heat,yang deficiency,yin deficiency,qi stagnation,blood stasis,dampness,and qi deficiency.The distributions of location factors as well as nature factors were significantly different dur-ing the whole procedure of CG progression,CNAG,CAG and finally PLGC.Conclusion During the procedure of:CNAG turned into CAG and into PLGC in the end,the evolvement characteristic of “sthe-nia transforming into asthenia and appearing yin deficiency and blood stasis gradually”was found.