An online enrichment-separation system of C18 and inductively coupled plasma-mass spectrometry (ICP/MS) with flow injection （C18-FI-ICP/MS） was established for the determination of trace heavy metals in seawater. The optimized experimental parameters including pH，C18 column，concentration of methol in elute and the velocity of elute were investigated. This system was applied to the online preconcentration , separation and determination of trace heave metals in seawater samples successfully. The detection limit　(3σ) for Cd, Pb, Co, Ni and Zn was 0.03, 0.09, 0.1, 0.1, 0.3 μg/L respectively. The RSD of Cd, Pb, Co, Ni, and Zn for six measurements of seawater was 6.8%，3.4%，1.3%，2.6%，0.5%，respectively. The accuracy was verified with spiked recovery test. The recovery for five elements was 91.3%，95.1%，100.4%，100.3%，95.2%, respectively.

Objective To analyze the epidemiological characteristics of malaria in Nanjing City,so as to provide the evi?dence for further formulating and adjusting the malaria prevention and control strategy. Methods The data of malaria situation, malaria cases and epidemiological investigations were collected from the Internet Reporting System in Nanjing City from 2010 to 2015 and analyzed statistically. Results A total of 137 confirmed malaria cases were reported in Nanjing City from 2010 to 2015,including 102 falciparum malaria cases(74.45%),33 vivax malaria cases(24.09%),one ovale malaria case(0.73%) and one quartan malaria case(0.73%). Among the 137 malaria cases,126 cases(91.97%)were imported from foreign coun?tries,2 cases(1.46%)were infected locally,and nine cases(6.57%)were imported from other provinces in China. Among the 126 overseas imported cases,117 cases were imported from African countries and 9 from Asian countries. These malaria cases were majorly young men working as migrant workers,laborers and technical persons. About 19.30%of the cases went to hospital on onset day,and 55.65%were confirmed by medical institutions as malaria in the same day. The majority of diagnosis institu?tions were municipal hospitals(74.45%). Conclusions The number of malaria cases in Nanjing City is declining year by year. The local infections are eliminating gradually. However,the situation of imported malaria from overseas is still serious. There?fore,the surveillance work and health education still should be strengthened,so as to reduce the risk of imported malaria.

Objective To master the current status of iodine nutrition of people in Nanjing after the adjustment of iodized salt standard,and to provide scientific basis for reasonable iodine supplementation and strategies for iodine nutrition control.Methods The probability proportional to size (PPS) sampling method was employed in the investigation.We firstly selected 30 streets in the whole city,and then chosen 50 children aged 8-10 years from each of 30 primary schools respectively,which was selected from 30 different streets to examine the size of thyroid gland by palpation and B-type ultrasound.We also collected urine and edible salt samples from 12 children aged 8-10 years from each primary school,to detect their urinary and salt iodine content.Moreover,20 pregnant women and 10 lactating women were picked out from each of 30 schools nearby to detect their urinary and salt iodine content.We also conducted a unique questionnaire survey in 30 fifth-grade students selected from each of 30 schools,and 5 housewives selected from these schools nearby to understand their knowledge of iodine deficiency disorders.Results The thyroid palpate swelling rate was 0.33％(5/1 500) in 1 500 children aged 8-10.The medians of urinary iodine level were 220.5 μg/L in 362 school-age children,196.7 μg/L in 600 pregnant women and 152.0 μg/L in 300 lactating women.A total of 1 260 samples of edible salt were tested.The coverage rate of iodized salt and the consumption rate of eligible iodized salt were 99.7％ (1 256/1 260) and 96.9％ (1 221/1 260),respectively.The mean iodine content of edible salt was (24.5 ± 4.5) mg/kg.A total of 900 fifth-grade students and 150 housewives were surveyed for health knowledge of iodine,and the eligible rate was 83.2％ (2 246/2 700) and 91.6％ (412/450),respectively.Conclusions After the adjustment of iodized salt content,iodine nutrition level of people in Nanjing has maintained appropriately.However,health education should be further strengthened.Improving the awareness rate of iodine deficiency knowledge,and guiding scientific iodine consciousness are our serious task in the future.

SuperparamagneticSiO2@Fe3O4microspherewithcore-shellstructurewaspreparedbythe method of hydro-thermal and St?ber method, and modified by (3-aminopropyl) triethoxysilane ( APTES) . The obtained amino-Fe3 O4@SiO2 microsphere with controlled surface charge properties was characterized by SEM and TEM, and the surface electric property of amino-microsphere was investigated by Zeta potential measurement. The microsphere was used to extract DNA from human blood, and the solid phase extraction method by microspheres was developed. The mechanism of action between Aminated-Fe3 O4@SiO2 microsphere and DNA was explored, and the gel electrophoresis and PCR test were done on the extraction product. The result showed that genomic DNA with high purity was successfully extracted from whole blood by using amino-Fe3 O4@SiO2 microsphere, with the extraction rate about 70%, the saturated adsorption capacity for DNA was about 40 ng/μg, and the elution could be directly used for further bio-analysis.

Objective To observe the development of Schistosoma japonicum after single sexual infection and double sexual infection respectively. Methods A single Oncomelania hupensis snail was infected by a single schistosome miracidium. The lar?va were induced and released from the snail after 60?day incubation at 26℃. The mice were infected by the larva(single sexual infection)and dissected 40 days after the infection. All the worms were collected and the sex of the larvae was determined by the sex of the adult worms. Then,the mice and rabbits were infected by single sex of larvae(single sexual infection)and double sex of larvae(double sexual infection)respectively. The mice and the rabbits were dissected 40 days after the infection. All the worms were collected and measured under a microscope. Results All the male or female worms were collected from the mice and rabbits after single sexual infection. There were three main forms of worms after dissection of double sexual infection of mice and rabbits:folded mature male and female,male or female. Few folded male and immature female were found. Only the double sexual larva infected mice or rabbits had schistosome eggs in the liver and the liver had typical schistosome egg nodules. The sin?gle sexual larva infected mice or rabbits had no schistosome eggs or schistosome egg nodules in the liver tissues. The single male larva could develop to worms with the testis,and with a little smaller size compared to the mature folded male,while the single sexual infection female worm could not develop to the mature stage with much thinner and smaller compared to the mature folded female. Conclusions The male or female worms from single sexual infection are smaller than those from double sexual infection (mature worms?folded male and female). So it is necessary to check single sex worms in vessels of intestinal mucosa thoroughly in the sentinel mice when no schistosome eggs were found in the liver.

Objective: To compare the effectiveness before and after the adjustment of schistosomiasis control strategies in Nanjing City, so as to provide the evidence for improving schistosomiasis control interventions. Methods: The prevalence of Schistosomasis japonicum infections in humans, livestock, Oncomelania hupensis and sentinel mice was collected in Nanjing City from 1993 to 2018, and the prevalence of S. japonicum infections in humans, livestock, sentinel mice and O. hupensis, and the areas of snail habitats, areas of infected snail habitats and snail control areas were compared before (1993-2004) and after (2005-2018) the adjustment of schistosomiasis control strategies to evaluate the effectiveness. Results: The prevalence of S. japonicum infections in humans, livestock, O. hupensis and sentinel mice was 0.77% and 0.02% (χ2=6 430.634, P<0.001), 0.46% and 0.01% (χ2=344.401, P<0.001), 0.19% and 0.11% (χ2=239.685, P<0.001), and 34.35% and 1.56% (χ2=1 856.286, P<0.001) in Nanjing City before and after the adjustment of schistosomiasis control strategies, respectively. The median areas (interquartile range) of snail habitats, infected snail habitats and snail control were 4 175.37 (1 301.65) and 2 366.44 (885.27) hm2 (Z=-3.755, P<0.001), 870.49 (1 001.75) and 0 (158.89) hm2 (Z=-3.654, P<0.001) and 1 383.23 (793.57) and 5 031.94 (629.11) hm2 (Z=-4.320, P<0.001) in Nanjing City before and after the adjustment of schistosomiasis control strategies, respectively. Conclusions After the adjustment of schistosomiasis control strategies, remarkable effects on schistosomiasis control has achieved in Nanjing City, where the transmission of schistosomiasis was interrupted. Nevertheless, the strategy requires to be continued and improved to move towards elimination of schistosomiasis in Nanjing City.

Objectives To investigate MRI patterns of functional connectivity(FC)in different brain areas of the subthalamic nucleus (STN)in Parkinson's Disease (PD)and its correlation with cognition.Methods We used functional magnetic resonance imaging to investigate the difference in whole-brain resting-state FC of STN between 32 patients with PD during the medicatiom ON state and 25 healthy control group(HC)matched for age,gender,and cognition,and examine the correlation between functional connectivity strength and montreal cognitive assessment (MoCA)scores.Results Compared with HC,the PD group showed increased FC in the right lingual gyrus of the left STN and the right STN showed decreased FC in the left superior frontal gyrus and the supplementary motor area(t=4.29,-3.61,and-3.83,respectively,each P ＜ 0.05),while the right STN showed only decreased FC in the right bilateral cingulate gyrus and the precuneus(t=-4.44,4.29,and-4.30,respectively,each P＜ 0.05).In addition,PD patients' connectivity strength between RSTN and the bilateral precuneus was positively correlated with MoCA scores(t =0.58 and 0.57,respectively,each P＜0.05).Conclusions Compared with HC,PD patients exhibit decreased FC between RSTN and the precuneus,with FC strength positively correlated with MOCA scores.The cognitive decline caused by deep brain stimulation in STN may be related to injuries of the precuneus.

Objective To evaluate the effect of comprehensive control for schistosomiasis with emphasis on environmental modification in the Bianmin River water system of Nanjing City.so as to provide scientific evidence for making up further control measures in this water system.Methods Schistosome infections of Oncomelania snails in the waterway.sentinel mice in water and neighbouring human were investigated longitudinally from 1998 to 2007,and the changes of huaman infection rates in differentyears,the infection rates of sentinel mice and snails in different settings were analyzed and compared.Results A total of 77 395 snails collected from the Bianmin River water system were dissected from 1998 to 2007,and among them,27 snails were infected with Schistosoma japonicum,with a total snail infection rate of 0.03%.A total of 61 039 snails collected from the neighbouring marshland which connected to the Yangtze River wore dissected,and among them,257 were infected with S.japonicum,with a total snail infection rate of 0.42%,and there was a significant difference compared with that in the water system(χ~2=248.55,P<0.01).After the protection works in the waterway,the infection rates of sentinel mice in the water system decreased from 69.68% in 1998 to 17.50% in 2001.with a reduction rate of 74.89%.Two years afterthe clearance ofmarshlandinthewaterway,no infected sentinel mouse was found.The infection rates of residents from 1998 to 2007 were 1.96%,1.37%,1.34%,1.60%,0.30%, 0.26%,0.16%,0.10%,0.04% and 0,respectively,andthe rates declined year by year afterthecomprehensive control.Conclusions The control measures based on the elimination of snail habitats in the waterway that is connected to the Yangtze River have achieved obvious effect.However,the clearance of the re-emerging snail habitats should be carried out termly to consolidate the control effect.

Objective To investigate the distribution of-6411A/G (rs208679) polymorphism in the 5' region of catalase (CAT) gene among Han population in Chongqing and its correlation with noiseinduced hearing loss (NIHL).Methods A total of 225 healthy volunteers (normal control group) and 237 noise exposure cases (noise exposure group) were collected from the unrelated Han people in Chongqing.The noise exposure group were further divided into non-deaf group (n =170) and deaf group (n =67) according the presence or absence of NIHL.rs208679 polymorphism in the 5' region of CAT gene was identified using the improved multiplex ligation detection reaction (iMLDR) technique.Genotypes,allelic frequencies and clinical deaf incidence were compared among groups.Results Three genotypes (AA,AG,and GG) were detected in the rs208679 locus.Frequencies of A and G alleles in normal control group and noise exposure group were 0.76 and 0.24 respectively.Genotype distribution in normal control group and noise exposure group showed no deviation from the Hardy-Weinberg equilibrium (P ＞0.05).There were no significant differences in gene polymorphism (AA,AG,and GG) and allelic frequencies (A and G) between normal control group and noise exposure group and between deaf group and non-deaf group (P ＞ 0.05).However,significant difference was observed between deaf group and non-deaf group in recessive analysis (GG vs AG + AA,P ＜ 0.05).Conclusion rs208679 is the predisposing gene to NIHL and can be used as the biomarker for NIHL susceptibility.

Based on the selective permeability of cationic exchange membrane and the characteristic of electri cal driven, a new and non-damage apparatus that can be used to separate compounds with different electric property was built to capture and enrich DNA.λ-DNA, as a model compound, was used to study the charac teristic of capturing and enriching DNA in this device.Factors that might affect the efficiency such as voltage and flow speed were optimized and gel electrophoresis was done to study if DNA was denaturation, PCR was done to prove the concentration can be used to further bioanalysis.Results were got; the apparatus could used to capture and enrich DNA scathelessly under the condition of low-voltage, the concentrate multiple was 62, and the recovery efficiency was accessible to 47%, concentration can be used for the next bioanalysis.Auto matic, easy to handle and little organic reagent using made it be advantageous, it could be miniatured to com bine with other biochips.This method had a large application space in field of DNA extraction, purification and concentration.