In this study,a method for detecting heavy metal ions using potentiometric sensor and voltammetric sensor was proposed.By exploiting the complementary advantages of potentiometric and voltammetric electrochemical sensor,the traditional electrochemical electrode without special material preparation and modification could be used for the wide range and accurate detection of heavy metal ions in actual water samples.During detection,the concentration of target ion was measured by a potentiometric electrochemical sensor to determine the concentration range.The amperometric electrochemical sensor was then used for calibration and accurate measurement in the appropriate concentration range.Taking copper ion(Cu2+)as an example,the prepared Cu2+water sample and the actual water sample were tested.First,the copper ion selective electrode was used to determine the concentration range of Cu2+in the sample.Then,based on the gold electrode in different concentration range(0.86-100 μg/L and 100-300 μg/L)using two different optimization parameter settings to calibrate the electrochemical sensor and measure,the test results had a good correlation with those by professional water quality testing institutions.The recoveries ranged from 86.7%to 103.0%.The experimental results showed that the combination of potential sensor and current sensor could improve the accuracy of detection of heavy metal ions in water samples by electrochemical sensor.

OBJECTIVE: To explore the influencing factors of low back pain and the relationship of the influence of bad working posture, weight load and frequency of load and the dose-response relationship among the occupational workers of key industries in China. METHODS: A total of 57 501 employees from 15 key industries in China were selected as research subjects using stratified cluster sampling method. The occurrence of low back pain in the past one year, as well as occupational factors such as job type, labor organization and work posture were investigated by using the Chinese version Musculoskeletal Disorders Questionnaire. RESULTS: The prevalence of low back pain in the occupational population of key industries in China was 16.4%(9 448/57 501). Multivariate Logistic regression analysis showed that the risk of low back pain in females was higher than that in males(P<0.01). Married, obese, occasional and frequent smokers, and a history of lower back disease were associated with increased risk of low back pain(all P<0.05). The risk of low back pain was associated with older age, higher education level, and lower frequency of physical exercise(all P<0.01). The risk of low back pain was higher with longer working time, greater back curvature, and the high frequency of long standing and sitting position work, uncomfortable working posture, repeated operation per minute, and lifting>5 kg weight(all P<0.01). CONCLUSION: The influencing factors of low back pain in the occupational population of key industries in China include bad working posture, high frequency load, weight load and other individual factors. There is a dose-response relationship with low back posture load and frequency of load.

Objective:To develop a visualized nomogram with a predictive value to differentiate mass-forming chronic pancreatitis (MFCP) from pancreatic ductal adenocarcinoma (PDAC) patients with chronic pancreatitis (CP) history.Methods:The clinical and radiological data of 5 433 CP patients acoording to the Asia-Pacific Diagnostic Criteria between February 2011 and February 2021 in the First Affiliated Hospital of Naval Medical University were retrospectively analyzed, and 71 PDAC patients with CP history and 67 MFCP who underwent surgery or biopsy and pathologically confirmed were eventually enrolled. The training set included 44 patients with MFCP and 59 patients with PDAC who were diagnosed between February 2011 and April 2018. The validation set consisted of 23 patients with MFCP and 12 patients with PDAC who were diagnosed between May 2018 and February 2021. Univariate and multivariate logistic regression analyses were performed to develop a prediction model for PDAC and MFCP, and the model was visualized as a nomogram. ROC was used to evaluate the predictive efficacy of the nomogram, and the clinical usefulness was judged by decision curve analysis.Results:The univariate analysis showed that a significant association with pancreatic cancer were observed for the duct-to-parenchyma ratio ≥0.34, pancreatic duct cut-off, pancreatic portal hypertension, arterial CT attenuation, portal venous CT attenuation, delayed CT attenuation, and vascular invasion in both the training and validation cohorts, but the duct-penetrating sign in the training cohort only. The multivariable logistic regression analysis showed that statistically significant differences (all P value <0.05) existed in cystic degeneration, a duct-to-parenchyma ratio ≥0.34, the duct-penetrating sign, pancreatic portal hypertension and arterial CT attenuation between the two cohorts. The above parameters were selected for the logistic regression model. The predicted model=3.65-2.59×cystic degeneration+ 1.26×duct-to-parenchyma ratio≥0.34-1.40×duct-penetrating sign+ 1.36×pancreatic portal hypertension-0.05×arterial CT attenuation. Area under the curve, sensitivity, specificity and accuracy of the model-based nomogram were 0.87 (95 CI 0.80-0.94), 89.0%, 75.0% and 83.5% in the training cohort, and 0.94 (95 CI 0.82-0.99), 91.7%, 100% and 97.1% in the validation cohort, respectively. Decision curve analysis showed that when the nomogram differentiated MFCP from PDAC patients with CP history at a rate of 0.05-0.85, the application of the nomogram could benefit the patients. Conclusions:The nomogram based on CT radiological features accurately differentiated MFCP from PDAC patients with CP history and provide reference for guiding the treatment and judging the prognosis.

Objective:To investigate the relationship between the perineural invasion score based on multidetector computed tomography (MDCT) and extrapancreatic perineural invasion (EPNI) in pancreatic ductal adenocarcinoma (PDAC).Methods:The clinical, radiological, and pathological data of 374 patients pathologically diagnosed as pancreatic cancer who underwent radical resection in the First Affiliated Hospital of Naval Medical University from March 2018 to May 2020 were analyzed retrospectively. Patients were divided into EPNI negative group ( n=111) and EPNI positive group (n=263) based on the pathological presence of EPNI. The perineural invasion score was performed for each patient based on radiological images. Univariate and multivariate logistic regression models were used to analyze the association between the perineural invasion score based on MDCT and EPNI in PDAC. Results:There were significant statistical differences between EPNI negative group and positive group on both pathological characteristics (T stage, N stage, invasion of common bile duct, and positive surgical margin) and radiological characteristics (tumor size, vascular invasion, lymph node metastasis, perineural invasion score based on MDCT, pancreatic border, parenchymal atrophy, invasion of duodenum, invasion of spleen and splenic vein and invasion of common bile duct) (all P value <0.05). Univariate analysis revealed that the tumor size, vascular invasion, lymph node metastasis, perineural invasion score based on MDCT, pancreatic border, pancreatic atrophy, invasion of duodenum, invasion of spleen and splenic vein and invasion of common bile duct were independently associated with EPNI. Multivariate analyses revealed that the perineural invasion based on MDCT was an independent risk factor for EPNI in pancreatic cancer (score=1, OR=2.93, 95% CI 1.61-5.32, P<0.001; score=2, OR=5.92, 95% CI 2.68-13.10, P<0.001). Conclusions:The perineural invasion score based on MDCT was an independent risk factor for EPNI in pancreatic cancer and can be used as an evaluation indicator for preoperative prediction of EPNI in PDAC.

Bismuth modified boron doped diamond (BDD) film electrode was employed for simultaneous determination of trace ZnⅡ,CdⅡand PbⅡby anodic stripping voltammetry.BiⅢwas simultaneously in-situ deposited on bismuth modified boron doped diamond electrode with ZnⅡ,CdⅡ and PbⅡ by pre-concentration.In the presence of BiⅢ,the sensitivity for determination of ZnⅡ,CdⅡ and PbⅡ was remarkably enhanced.Influence factors such as bismuth concentration,boron doped concentrations of BDD electrode,pH,preconcentration potential were investigated and optimized.Under the optimal conditions,the stripping peak currents increased linearly with the increasing concentration of ZnⅡ,CdⅡ and PbⅡ in the range of 10-300 μg/L.The limit of detection was 0.56 μg/L for ZnⅡ,0.32 μg/L for CdⅡand 0.75 μg/L for PbⅡ (S/N=3),respectively.The interference experiments showed that common ions had little influence on the determination except CuⅡ.In addition,the developed electrode displayed a good repeatability.The method was successfully applied to determination of ZnⅡ,CdⅡ and PbⅡ in real water samples with the standard addition recoveries of 92.0%-114.0%.

This cross-sectional study aimed to examine the association between selenium levels and diabetes in an older population with life-long natural exposure to selenium in rural China. A total of 1856 subjects aged 65 years or older from four Chinese rural counties with different environmental selenium levels were evaluated. Analysis of covariance models and logistic regression models were used to examine the relationship between nail selenium levels and serum glucose, serum insulin, insulin resistance [using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)], and the risk of diabetes. The mean nail selenium level was 0.461 μg/g and the prevalence rate of diabetes was 8.3% in this population. The mean nail selenium level was significantly higher in the group with diabetes than in the group without diabetes (P<0.0001). The adjusted odds ratios for diabetes were 2.65 (95% CI: 1.48 to 4.73), 2.47 (95% CI: 1.37 to 4.45), and 3.30 (95% CI: 1.85 to 5.88) from the second selenium quartile to the fourth quartile, respectively, compared with the first quartile group. The mean serum glucose and HOMA-IR in the higher selenium quartile groups were significantly higher than those of the lowest quartile group. However, no significant differences in insulin were observed among the four quartile groups. A long-term, higher level of exposure to selenium may be associated with a higher risk of diabetes. Future studies are needed to elucidate the association between selenium and insulin resistance.
Aged ; Aged, 80 and over ; China ; Cross-Sectional Studies ; Diabetes Mellitus ; metabolism ; Female ; Humans ; Male ; Nails ; metabolism ; Rural Population ; Selenium ; metabolism

Objective To investigate the effect of non invasive cardiac output monitoring(NICO)system in pig model with acute respiratory distress syndrome(ARDS),and to provide experimental basis for clinical application. Methods Eleven anaesthetized and ventilated ARDS male pig models were induced by intravenously infusing 0.2 mL/kg oleic acid. Lung recruitment was condocted by pressure control ventilation on pigs with ARDS. The optimal positive end-expiratory pressure(PEEP)was determined by optimal dead space fraction〔the ratio of dead space to tidal volume(VD/VT)〕. Cardiac output(CO)was determined by NICO,the respiratory function was monitored, and the VD/VT,dynamic compliance(Cdyn),oxygenation index(PaO2/FiO2),the volume of alveolar ventilation(Valv) and arterial blood oxygen saturation(SaO2)were recorded before infusing oleic acid,after stabilization of ARDS model and at optimal PEEP level,and the intrapulmonary shunt fraction(Qs/Qt)was calculated. CO was also determined by application of pulse indicated continuous cardiac output(PiCCO),and the linear regression analysis between CO determined by NICO and CO determined by PiCCO was conducted. Results Seven experimental ARDS pigs model were successfully established. The optimal PEEP identified by the lowest VD/VT method was(15.71±1.80)cmH2O (1 cmH2O=0.098 kPa). Compared with before infusing oleic acid,VD/VT and Qs/Qt after stabilization of ARDS model were significantly increased〔VD/VT:(72.29±8.58)% vs.(56.00±11.06)%,Qs/Qt:(21.04±15.05)%vs.(2.00±1.32)%,both P<0.05〕,and SaO2 and Valv were significantly decreased〔SaO2:0.888±0.108 vs. 0.999±0.053,Valv(mL):92.06±35.22 vs. 146.11±45.43,both P<0.05〕. VD/VT,Qs/Qt,SaO2 and Cdyn at optimal PEEP level were improved to the levels before infusing oleic acid〔(61.07±9.30)%,(3.21±6.10)%, 0.989±0.025,(117.14±41.14)mL〕. Cdyn and PaO2/FiO2 after stabilization of ARDS model were significantly lowered compared with those before infusing oleic acid〔Cdyn (mL/cmH2O):14.43±5.50 vs. 38.14±6.72, PaO2/FiO2 (mmHg, 1 mmHg=0.133 kPa):78.71±23.22 vs. 564.37±158.85, both P<0.05〕. Cdyn and PaO2/FiO2 at optimal PEEP level〔(19.71±4.86)%,(375.49±141.30)mmHg〕were elevated compared with the levels after stabilization of ARDS model(both P<0.05),but still lower than those before infusing oleic acid(both P<0.05). Compared with the levels after stabilization of ARDS model,CO at optimal PEEP level showed obvious decrease from(4.18±2.46)L/min to(3.95±2.69)L/min without significant difference(P>0.05). There was linear correlation between CO determined by NICO and CO determined by PiCCO(r2=0.925,P<0.001). Conclusions NICO technique provides a useful and accurate non invasive estimation of CO and respiratory function.VD/VT provided by NICO can titrate the optimal PEEP in patients with ARDS.

OBJECTIVETo evaluate the feasibility and efficiency of embolization of spinal dural arteriovenous fistula (SDAVF).

METHODSFrom December 2010 to May 2012, there were 104 cases of SDAVF were treated, and 26 cases were selected to be treated with embolization. The inclusion criteria was as follows: (1) No anterior or posterior spinal artery originated from the fistula segment; (2) The segmental artery can be catheterized with guiding or micro catheter; (3) High flow in fistula; (4) Patient's situation was not suitable for surgery or general anesthesia. Among 26 cases, there were 22 male and 4 female patients, the average age was 55.9 years (ranged from 34 to 81 years). The locations of SDAVF were 10 cases in thoracic, 9 in lumbar and 7 in sacral segment. The main symptoms were progressive numbness and weakness in both lower extremities, most cases accompanied with difficulties in urination and defecation. The average history was 17.1 months (from 1 to 156 months). ONYX-18 liquid embolic agent or Glubran-2 surgical glue were used as embolic material. The patients not cured with embolization were treated with surgery in the following 1 - 2 weeks. Follow-up evaluation was done with MRI after 3 months and DSA after 6 months, besides physical examination.

RESULTSFifteen from 26 cases achieved immediate angiographic cure results: 14 in 20 cases which embolized with ONYX-18; only 1 in 6 cases with Glubran-2. Three in 10 cases of thoracic SDAVF and 12 in 16 cases of lumbar/sacral SDAVF were cured with embolization. Partially embolized cases were treated with surgical obliteration of drainage veins within 2 weeks. Cured patients experienced immediate improvement after embolization and kept getting better in the follow-up. All the patients had MRI follow-up after 3 months and DSA follow-up after 6 months. In 6 month's follow-up, MRI showed the edema and flow void signal in the spinal cord disappeared. DSA showed no fistula recurrence or remnant. There was no deterioration case in all of the embolized cases.

CONCLUSIONSParticular SDAVF is suitable for embolization with ONYX-18. Most lesions located in lumbar and sacral segment are good indications for embolization.

Adult ; Aged ; Aged, 80 and over ; Central Nervous System Vascular Malformations ; therapy ; Embolization, Therapeutic ; methods ; Feasibility Studies ; Female ; Humans ; Male ; Middle Aged ; Treatment Outcome

OBJECTIVETo detect the spatial distribution characteristics of iodine in drinking water of residents in Shandong province with spatial autocorrelation analysis.

METHODSThe county-based study set Shandong province as a research site. A total of 108 164 water samples from 140 counties were collected. The drinking water iodine data in county-level city between 2008 to 2010 were obtained from Shandong Institute of Prevention and Control for Endemic Disease and was merged with an electronic map to build a spatial database. Global and local Moran's I index were calculated, respectively, and spatial autocorrelation and cluster range of iodine distribution in drinking water in Shandong province were studied by SaTScan software.

RESULTSAll counties were further grouped according to the "criteria of delimitation for IDD endemic areas" and "determination and classification of the areas of high water iodine and the endemic areas of iodine excess goiter", and 90 counties were iodine deficiency (< 10 µg/L), 31 were iodine suitable (10 - 150 µg/L), and 19 (> 150 µg/L) were high iodine. For the overall study area, the iodine distribution in drinking water in Shandong province existed spatial autocorrelation (Moran's I = 0.52, Z = 7.4, P < 0.01). For the local scale, the drinking water iodine in 18 counties of Dezhou, Liaocheng and Heze city in western Shandong province was clustered, the local Moran's I were between 0.22 - 1.00 (P < 0.01), which were all high-high clusters, indicating the positive spatial correlation. Spatial analysis using SaTScan software detected two cluster areas including 20 counties, which the centers located in Xiajin and Dingtao county, the cluster radiuses were 57.47 km and 65.58 km respectively. The analysis results were consistent with the results of local spatial autocorrelation.

CONCLUSIONThere are apparent spatial autocorrelation and strong spatial heterogeneity existed in the iodine distribution in drink water in Shandong province.

China ; Cluster Analysis ; Drinking Water ; analysis ; Iodine ; analysis ; Spatial Analysis ; Statistical Distributions

Objective To understand the current situation of endemic fluorosis in Shandong Province,and to provide a scientific basis for development of control strategies.Methods In accordance with the requirements of the national Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis (Trial) and Shandong Provincial Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis (Trial),and to understand the progress of the province's water-improvement projects,10 counties were chosen in the province,and 10 water-improvement projects were selected in each county.Running condition of the water-improvement projects was investigated,and water fluoride content was tested.Three epidemic villages were chosen as fixed monitoring villages in each county.In each village,fluoride content in drinking water was determined,and dental fluorosis of all children aged 8 to 12 was diagnosed.Water fluoride content was determined by fluoride ion selective electrode method,and dental fluorosis of children aged 8 to 12 was diagnosed by Dean method.Results ① There were 3570 water defluoridation projects in the province,and water-improvement rate was 87.49％ (10 122/11 569).Normal operating projects accounted for 89.10％ (3181/3570),and the passing rate of water fluoride content was 73.14％ (2611/3570),with the maximum water fluoride as 9.71 mg/L.② In the 10 counties,a total of 86 waterimprovement projects were monitored.Normal operation,intermittent operation and scrapped projects accounted for 95.35％ (82/86),3.49％ (3/86) and 1.16％ (1/86),respectively,and passing rate of fluoride content in water was 50.00％ (43/86),and the maximum water fluoride was 5.32 mg/L.③ In the 27 monitored villages with improved water quality,the passing rate of fluoride content in water was 74.07％ (20/27),and the maximum water fluoride was 4.50mg/L.In the 3 monitored villages without improved water quality,villages of mean water fluoride ≤ 1.20 mg/L and ＞ 1.20 mg/L accounted for 33.33％ (1/3) and 66.67％ (2/3),respectively,and the maximum water fluoride was 1.53 mg/L.④ In the 27 monitored villages with improved water quality,the detection rate of dental fluorosis among children aged 8 to 12 was 57.65％(791/1372),and the detection rate of defect type dental fluorosis was 7.80％(107/1372); the index of dental fluorosis was 1.15.In the 3 monitored villages without improved water quality,the detection rate of dental fluorosis among children aged 8 to 12 was 50.97％ (80/155),and the detection rate of defect type dental fluorosis was 7.10％(11/155); the index of dental fluorosis was 1.16.Conclusions In Shandong Province,the running condition of water improvement project to reduce fluoride still needs to be further improved,and the water fluoride is seriously overweight and endemic fluorosis has not been effectively controlled.Preventive measures should be strengthened.