An instrumental analysis method for the determination of stable silicon isotope ratio using multi-collector inductively coupled plasma mass spectrometry ( MC-ICP-MS) was established. In dry plasma mode, silicon isotopes suffered from the spectrum polyatomic interferences of C, N, O, H at medium resolution. The sample gas flow had significant effect on the silicon sensitivity and signal stability. Besides, higher sample gas flow lead to higher production of 14N16O. Consistent δ29Si and δ30Si within 0. 04‰ (1σ) could be obtained over a mass range of ca. 9 milli-amu at the lower mass side of silicon at medium resolution. The analyte concentrations of the sample and reference material were matched within 20% to avoid concentration effect on the determination of silicon isotopes using standard-sample-bracketing correction method. The measurements were not sensitive to the acid molarity and Cl matrix. An internal precision of less than 8×10-6(1σ) could be achieved for 29 Si/ 28 Si and 30 Si/ 28 Si by taking an integration time of 8 seconds. The long-term reproducibility of 0 . 06‰-0 . 10‰ ( 2σ, n=20 ) was obtained for δ29 Si and δ30 Si by repeating the analysis of the silicon reference materials, whilst the determined isotopic value for GBW04421 and GBW04422 were in good agreement with the recommended data, suggesting the precision and robustness of this method. The measured silicon isotopic values of fresh waters ( river and lake waters ) , saline waters and seawater demonstrated the capability of applying this method to trace the biogeochemical processes of silicon in natural waters.

In order to explore the effects of diet and nutritional factors on breast cancer incidence, a case-control study was conducted in Tianjin. The study consisted of 244 cases diagnosed between September 1986 and September 1987 and equal number of matched controls from patients other than breast cancer in general hospital.The socio-demographic data, histories of menstruation and reproduction etc were collected by interview. The interview on diet was conducted by recalling the frequencies and amounts of various foods eaten one year prior to the diagnosis' of their current diseases. Data were analysed by using a nutrient-estimate program and conditional logistic regression model, chi square test and u-test.After adjusting for confounding factors, the results showed that high fat, high calorie, high monounsaturated fatty acid and low vitamin C intakes were risk factors for female breast cancer. High fat percentage of energy and low vegetable intake were associated with increased risk for breast cancer.

Objective To detect the dynamic change of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with major trauma and measure its relation to the outcome.Methods Sixty patients with major trauma were measured with serum NT-proBNP level at 1,3,and 7 days postinjury.According to the prognosis,the patients were allocated to survival group (n =47) and death group (n =13).Changes in NT-proBNP was detected and compared between the two groups.Correlation of NT-proBNP level with acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) and ISS was analyzed at each time point.Receiver operating characteristic curve (ROC) was developed to determine the prognostic value of NT-proBNP.Results Overall NT-proBNP level revealed no statistical difference at each time point and kept within normal reference range.NT-proBNP level in death group increased gradually,whereas in survival group the increase was followed by a reduction.Moreover,NT-proBNP level was higher in death group than in survival group at each time point.Area under the ROC of NT-proBNP had no statistical difference with that of APACHE Ⅱ and ISS at each time point.Conclusions Obviously high or continuously increased NT-proBNP level may indicate an unfavorable prognosis of major trauma patients.NT-proBNP can be used as a marker to dynamically predict prognosis of major trauma patients.

ObjectiveTo detect the serum NT-proBNP level in patients with severe trauma 24 hours after injury in order to find the possible correlated factors for the evaluation of the clinical application.MethodsSixty patients with severe trauma admitted to the emergency ICU were enrolled. Serum NTproBNP level was detected 24 hours after injury for comparison between survivors and nonsurvivors. The validity of NT-proBNP for predicting outcome was analyzed by receiver operating characteristic ( ROC )curve. The factors with significant correlation between NT-proBNP level and the length of ICU stay as well as the duration of mechanical ventilation support were determined in those survivors with correlation and stepwise linear regression analysis. These factors included injury severity score (ISS), head abbreviated injury score (AIS), acute physiology and chronic health evaluation Ⅱ ( APACHE I ), Glasgow coma score (GCS), creatine kinase-MB (CK-MB), cardiac troponin-I (cTn-I) and central venous pressure. Results The median NT-proBNP levels were 762 pg/ml (IQR, 400-1131 pg/mL) in nonsurvivors versus 200 pg/ml (IQR, 80-383 pg/mL) in survivors (Z =-3. 972, P ＜0.01 ). The area under ROC curve of NTproBNP was not statistically different to that of ISS and that of APACHE Ⅱ. The best threshold value of NTproBN to predict the outcome was 384 pg/ml ( sensitivity 0. 846, specifity 0. 766). A positive correlation was found between NT-proBNP and the length of ICU stay ( r =0. 32, P ＜ 0. 05 ) as well as the duration of mechanical ventilation ( r =0. 37, P ＜ 0. 05 ) in survivors. Stepwise linear regression analysis indicated there were significant correlations between APACHE Ⅱ, CK-MB and NT-proBNP.ConclusionsSerum NT-proBNP level 24 hours after injury is correlated with the severity and outcome of patients with severe trauma. It may be used as a complementary biomarker for the rapid assessment of the severity of trauma.

AIM: To compare the renoprotective effects of angiotensinⅡtypeⅠreceptor antagonist (AT 1RA) with that of angiotensin converting enzyme inhibitor (ACEI) and to investigate their influences on intrarenal renin-angiotensin system. METHODS: Experimental nephrotic syndrome model was induced in SD rats with repeated peritoneal injections of puromycin. Twenty-eight rats were randomly divided into four groups: normal control, nephrotic control, ACEI-treated and AT 1RA-treated group. Serum, urine and renal tissue were collected for study 12 weeks later. RESULTS: The urine protein was less and renal function was better in both treated groups. The glomerular and interstitial injury indexes of both ACEI and AT 1RA treated rats were lower than that of nephrotic control rats and had no significant difference between the two treated groups. The renal local ACE activity and angiotensinⅡ of nephrotic control group were significantly higher than that of normal control group and the two treated group(P

Objective To study 18F-deoxyglueose positron emission tomography computed tomo graphy(18 FDG PET-CT) in the diagnosis of cervical lymph node(LN) metastasis from rabbit nasopharyngeal VX2 carcinoma.Methods Nasopharyngeal VX2 carcinoma model using 30 rabbits was established. 18 FDG PET-CT,MRI and pathological diagnosis were performed and compared.ResultsFifty-three cervi cal LNs were picked up from resected specimens of 30 rabbits with nasopharyngeal VX2 carcinoma.There were 42 pathologically confirmed positive LNs.Positivity rate was significantly correlated with the volume and the shortest diameter of the LNs (r = 9.18,P =0.007 ; r = 2.77,P = 0.008).The diagnostic sensitivity of PET-CT was 96% (24/25) and 29% (5/17) for LNs with volume >0.5 cm3 and ≤0.5 cm3 ,83% (25/30) and 33% (4/12) for LNs with the shortest diameter ≥0.5 cm and < 0.5 cm,respectively.The diagnostic sensitivity,specificity and accuracy of PET-CT was 69% (29/42) ,100% (11/11) and 95% (40/42) ,com paring with 60% (25/42) ,91% (10/11) and 83% (35/42) of MRl,respectively.The volume measured by PET-CT images was not significantly different from the pathologically measured volume (t =-1.23,P = 0.233) ,while the volume measured by MRI was significantly different from the pathologically measured vol ume (t =-3.99,P = 0.001).Conclusions The sensitivity,specificity and accuracy of PET-CT are better than those of MRl,especially for the cervical lymph nodes with volume >0.5 cm3 or the shortest diameter ≤ 0.5 cm.PET-CT also can be used to detect the smaller metastatic lymph nodes,though the false negative rate is higher.

Objective To develop a probe for photoacoustic imaging and fluorescence imaging targeting integrin αvβ6 . Methods The probe was separated by RP‐HPLC .Molecular weight and the maximum absorption wavelength of the probe were detected by mass spectrum instrument and optical spectrum instrument . Various concentrations of the probe were detected by photoacoustic imaging and fluorescence imaging . The stability of the probe was evaluated when exposed under laser . Targeting of the probe on integrinαvβ6 was evaluated in cell uptake assay with integrinαvβ6 positive and negative cells . The minimum number of cells that could be detected by photoacoustic imaging and fluorescence imaging was also evaluated . Results The probe ICG‐peptide was separated from reaction mixture by RP‐HPLC .The probe had a retention time of 21 .4 minutes and m/z of 4 727 . The labeling ratio of the probe was 1∶1 . The maximum absorption wavelength of the probe was 790 nm . The photoacoustic signal was linearly dependent on the concentration of the probe . The fluorescence signal was linearly dependent on the concentration of the probe when the concentration was smaller than 1 .5 × 10 -5 mol/L . The lowest concentration of the probe that could be detected above the background by photoacoustic imaging and fluorescence imaging was 0 .09 × 10-5 mol/L and 0 .05 × 10-5 mol/L ,respectively . No obvious decrease of the photoacoustic signal was observed after the probe was scanned 20 times ( each time lasted for 1 min) by laser . There existed differences ( P <0 .001) in cell uptake of the probe with various concentrations and reaction time between A431 cells (αvβ6 positive) and 293T cells (αvβ6 negative) . Cell uptake was inhibited by the addition of 5μmol/L unlabeled peptide in A431 cells ( P = 0 .001 ) . The lowest number of the labeled A431 cells detected by photoacoustic imaging and fluorescence imaging was 0 .4 × 106 and 0 .05 × 106 ,respectively . Conclusions The dual functional photoacoustic and fluorescence probe targeting integrin αvβ6 was successfully developed . The targeting and sensitivity of the probe makes it potentially useful in early detection of αvβ6 positive tumors .

Objective To evaluate preoperative apparent diffusion coefficient (ADC) and exponential apparent diffusion coefficient (eADC) in diffusion weighted imaging (DWI) on microvascular invasion (MVI) of hepatocellular carcinoma (HCC).Methods We retrospectively reviewed 43 HCC patients with DWI data confirmed by surgery and pathology.ADC and eADC values were measured both in neoplasm and hepatic tissue,the ratio of tumor to liver (T/L) on ADC and eADC was calculated.The correlation between MVI and ADC value,T/L of ADC value,eADC value and T/L of eADC value was analysed,the best cut-off value of variables was analysed by ROC curve,multi factor analysis was carried out by Logistic regression model.Results The ADC value,T/L of ADC,eADC value and T/L of eADC were (1.458 ± 0.444) × 10-3 mm2/s,0.787 ± 0.186,0.289 ± 0.144 and 1.383 (1.179,1.655),respectively.Among them,the positive MVI group were (1.232 ± 0.480) × 10-3 mm2/s,0.683 ± 0.229,0.323 ±0.123 and 1.630(1.387,2.066),respectively.The negative MVI group were(1.545 ±0.404) × 10-3mm2/s,0.844 ±0.149,0.277 ±0.152 and 1.303(1.176,1.545),respectively.There was significant difference in ADC value,T/L of ADC value and T/L of eADC value (t =2.164,2.654,z =-2.058,all P ＜0.05),the area under the ROC curve were (1.085 × 10-3) mm2/s,0.685 and 1.475 using MVI as a diagnostic standard.Multivariate analysis showed that T/L of ADC value was an independent factor affecting MVI of HCC (OR=0.002,95％CI:1.380E-5-0.311,P＜0.05).Conclusions The ADC value in HCC patients with positive MVI is lower than in HCC patients with negative MVI,T/L of eADC value is higher than in HCC patients with negative MVI,and T/L of ADC value is an independent factor predicticing MVI of HCC.

Objective: To understand the incidence and mortality of colorectal cancer in tumor registration areas of Zhejiang Province,and to provide reference for prevention and control strategies for colorectal cancer. Methods: The colorectal cancer data was retrieved from fourteen tumor registries in Zhejiang Province were collected,the incidence rate and mortality rate were calculated and standardized according to the Chinese standard population in 2010 and Segi's world population in 2000. The incidence and mortality of colorectal cancer in different sex,age group and region were analyzed. Results: The crude incidence rate of colorectal cancer from 2010 to 2014 was 35.82/100 000（20 983 cases）. The standardized incidence rate by Chinese and world standard population were 20.80/100 000 and 23.01/100 000. The crude mortality rate of colorectal cancer was 15.25/100 000 （8 934 cases）. The standardized mortality rate by Chinese and world standard population were 8.01/100 000 and 9.39/100 000. The ratio of mortality to incidence was 0.43:1. From 2010 to 2014,the incidence and mortality rates of colorectal cancer were stable（P>0.05）. The incidence rates of colorectal cancer in urban and rural residents were 37.69/100 000 and 31.14/100 000,and the mortality rates were 15.73/100 000 and 14.05/100 000. The incidence rates of colorectal cancer in males and females were 41.53/100 000 and 30.11/100 000,and the mortality rates were 17.74/100 000 and 12.76/100 000. The incidence and mortality rates of colorectal cancer both increased with age. The incidence rate increased significantly in people after 40 years old,and peaked with 187.35/100 000 in people aged 80-84 years. The morbidity rate peaked with 171.27/100 000 in people aged 85 years or over. Conclusion The incidence and mortality of colorectal cancer in Zhejiang Province were stable,but the incidence was higher than the national average level. The incidence of colorectal cancer in people aged over 40 years increased significantly.

Objective To analyze the effect of clinical application of ultrasound in microsurgical treatment of intramedullary tumors in the superior cervical spinal cord.Methods Retrospective study the clinical data of 15 patients with intramedullary tumors in the superior cervical spinal cord,which were underwent a laminectomy for microsurgical tumor resection during January,2014 and January,2018.Intraoperative ultrasound and neuromonitoring was accompanied by the whole surgical procedure for each case.The follow-up data was collected by outpatient department visits and telephone interviews.Results All the described patients were performed with microscopic tumor resection by using intraoperative neurophysiological monitoring and ultrasound.The pathological diagnosis was ependymocytoma (n=8) and astrocytoma (n=7).Gross total resections comprised 86.7％ of cases (n=13),and subtotal resections 13.3％ (n=2).The neurological outcome was as follows:Mc-Cormick scale grade Ⅰ,10 patients;grade Ⅱ,3 patients;grade Ⅲ,1 patient;and grade Ⅳ 1 patient;Follow-up was applied for (19.2±7.6) months in 13 cases and 12.0 months in 2 cases.Compared to the preoperative period,66.6％ of patients recovered postoperatively,20.0％ improved,6.7％ remained without deficit and deterioration persisted in 6.7％.Conclusion The microscopic resection of tumors is the effective way to cure this disease.By using intraoperative neurophysiological monitoring and ultrasound,the complete tumor resection and the minimal spinal cord injury were certainly achieved.