Dental Bonding ; methods ; Dentin ; Dentin-Bonding Agents ; chemistry ; Electricity ; Humans

Objective To improve the current standard method of measuring urinary iodine by As (Ⅲ)-Ce4+catalytic spectrophotometry, reducing the amount of arsenic toxic reagent used to decrease environmental pollution,and make the modified method with good precision and accuracy. Methods For improving the current standard method of measuring urinary iodine, amount of arsenious acid solution was reduced from 0.100 mol/L H3AsO3(which contains NaCl 25 g/L) 2.5 ml to 0.025 mol/L H3AsO3(which contains NaCl 40 g/L) 2.5 ml;amount of ceric ammonium sulfate solution was reduced from 0.076 mol/L 0.30 ml to 0.025 mol/L 0.30 ml;photometric wavelength was changed from 420 nm to 400 nm. The new modified method was evaluated by standard curve linearity and linear range, sample detection limit, precision, accuracy, and urinary iodine values, and the rates of absorbance change in the test process were compared with the current standard method. Results The calibration relation of C= a + blgA (C: iodine concentration, A : measuring absorbance) in the new modified method existed when As3+-Ce4+ catalytic reaction was kept at a certain stable temperature range between 20 - 35 ℃ and in certain stable reacting time. The linear range of the calibration curve was 0 - 300 μg/L and the linear correlative coefficient was - 0.9998. The detection limit for iodine was 4 μg/L(0.25 ml of urine was tested). The test coefficient of variations(CV) were 1.7%(1.1/66.0), 1.8%(1.4/76.0), 2.0%(3.0/147.5), 1.6%(4.2/265.5) when measuring urine samples with iodine concentration of 66.0, 76.0, 147.5, 265.5 μg/L, respectively. The average recovery was 100.6% with a range of 95.0% (57.0/60.0) - 103.7% (62.2/60.0) when measuring 4 urine samples containing different iodine concentration, and average recovery was 101.0% (40.4/40.0), 100.4% (100.4/I00.0), 100.5% (60.3/60.0),100.4% (100.4/100.0), respectively. The test results of two national standard urinary iodine were all within the given value range and the relative deviation(RD) was < 5.0% and < 2.0% in 20, 25, 30, 35 ℃ test temperature,respectively. No significant difference was found between the results of the 48 urine samples determined by the new modified method and the current standard method(t = 0.634, P > 0.05). The table of suitable combination of As3+-Ce4+ reaction temperature and time for this method was obtained(such as 20 ℃ and 53 min, 25 ℃ and 40 min, 30 ℃and 30 min, etc. ). Compared with the standard method, the rates of absorbanee change of As ( Ⅲ )-Ce4+ reaction in the new modified method were more slowly, which further reducing the determination deviation caused by the temperature fluctuations or measuring time deviation in measurement process. Conclusions This new modified method greatly reduces the amount of arsenic in waste, reduces pollution, saving reagents, and this method is easier to operate with better precision and accuracy, which is suitable for application of measuring iodine in urine.

Objective To observe the changes of the intercellular spaces of squamous epithelium of lower esophagus in gastroesophageal reflux disease(GERD).Methods Eleven outpatients with GERD symptoms more than 3 months [6 with nonerosive reflex disease(NERD)and 5 with erosive esophagitis(EE)]and 5 healthy volunteers were recruited.All of them underwent endoscopy and 24-hr ambulatory pH monitoring.Biopsies were taken in lower esophagus(2 cm above Z-line)for electron microscope examination.Results Intercellular spaces of esophageal epithelial cell in volun teers,NERD patients and EE patients were (0.374?0.073)?m,(1.308?0.079)?m and (1.332?0.144)?m respectively,with significant differences between the control group and the NERD or EE group.There was no difference between NERD group and EE group.Conclusions Dilated intercellular spaces were seen in both NERD and EE cases,which was significantly different from the control cases.

Objective:To investigate the correlation between hyperreflective dots (HRD) and lipid levels and systemic inflammatory factors in patients with branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO).Methods:A cross-sectional clinical study. From December 2016 to June 2020, 118 eyes of 118 patients with retinal vein occlusion diagnosed in the Department of Ophthalmology, Central Theater Command Hospital of People's Liberation Army were included in the study. Among them, 67 cases of BRVO and 51 cases of CRVO were divided into CRVO group and BRVO group accordingly. Peripheral venous blood was drawn from the patients within 3 days after the eye examination to detect the percentage of neutrophils, monocytes, hypersensitive C-reactive protein (CRP), total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and lipoprotein(a). The ratio of monocytes to high-density lipoprotein (MHR) was also calculated. The 3D OCT-2000 instrument from Topcon (Japan) was used to measure the central retinal thickness (CRT) and the numbers of HRD. According to the different distribution position, HRD is divided into inner retina HRD, outer retina HRD, and total retina HRD.The independent sample t test was used to compare the continuous variables of the two groups, and the χ2 test was used to compare the rates. The correlation between HRD counts and blood lipid levels and peripheral blood inflammation indicators in patients with different types of RVO was analyzed by Spearman correlation analysis. Results:The average age of patients in the BRVO group and CRVO group were 60.1±9.5 and 53.6±15.7 years, respectively; the prevalence of hypertension was 53.7% (36/67) and 24.5% (12/51), respectively. Comparison of age ( t=2.634) and prevalence of hypertension ( χ2=11.298) between the two groups showed statistically significant differences ( P<0.05). Gender ( χ2=2.000), course of disease ( t=-1.101), prevalence of diabetes ( χ2=1.315), eye category ( χ2=1.742), baseline visual acuity ( t=1.792), intraocular pressure ( t=0.708), CRT ( t=1.318), and peripheral blood include the percentage of neutrophils, the absolute number of monocytes, CRP, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, lipoprotein(a), MHR ( t=-0.559, 1.126, 0.579, 1.299, -0.134, 0.556, 1.230, -0.267, 0.483), the difference was not statistically significant. Correlation analysis showed that the HRD counts in the outer retina of BRVO patients were positively correlated with total cholesterol ( r=0.289, P=0.036); the HRD in the inner retina and total HRD counts of CRVO patients were positively correlated with CRP ( r=0.406, 0.343; P=0.004, 0.014). There was no correlation between HRD counts and percentage of neutrophils, absolute number of monocytes, triglycerides, high-density lipoprotein, low-density lipoprotein, lipoprotein(a), and MHR ( P>0.05). Conclusion:The number of HRD is related to the blood lipid level in BRVO patients and CRP (an inflammatory index) in CRVO patients.

ObjectiveTo establish a new method with low usage amount of arsenic trioxide for measuring 300 - 1200 μg/L high concentration iodine in urine by As3+-Ce4+ catalytic spectrophotometry using ammonium persulfate digestion, which would be convenient for monitoring urinary iodine in excessive iodine regions and to reduce environmental arsenic pollution. Methods Calibrators and urine samples(0.20 ml each) were digested according to the current standard detection method of urinary iodine(WS/T 107-2006). At the same time, improving the current standard method, the amount of arsenious acid solution was reduced from 0.100 moL/L H3AsO3 (containing NaCl 25 g/L) 2.5 ml to 0.025 mol/L H3AsO3(containing NaCl 40 g/L) 2.5 ml; amount of ceric ammonium sulfate solution was reduced from 0.076 mol/L 0.30 ml to 0.025 mol/L 0.50 ml; and photometric wavelength was changed from 420 nm to 380 nm. The new method was evaluated by standard curve linearity and linear range, sample detection precision, accuracy, and the results of urinary iodine were compared with those determined bycurrent standard method, and this new method was also tested of suitable combination of reaction temperature and reaction time of cerium arsenic in the temperature range of 20 - 30 ℃. Results The calibration relation of C =a + blgA (C: iodine concentration, A : measuring absorhance) in the new method existed when As3+- Ce4+ catalytic reaction was kept at a certain stable temperature range between 20 - 30 ℃ and in certain fixed reacting time. The linear range of the calibration curve was 300 - 1200 μg/L and the linear correlative coefficient was- 0.9999. The relative standard deviations(RSD) were 1.0％(3.2/330.3), 0.4％(2.0/517.3), 0.5％(3.9/712.6) and 0.9％(9.4/1042.3) when measuring urine samples with iodine concentration of 330.3, 517.3,712.6, and 1042.3 μg/L, respectively. The total average recovery was 98.3％ with a range of 93.4％ (186.8/200.0) - 101.5％ (202.9/200.0) when measuring 4 urine samples containing different concentration of high iodine, and average recovery was 99.1％ (148.6/150.0), 97.5％ (195.0/200.0), 98.8％ (395.3/400.0), and 98.2％ (392.7/400.0),respectively. The test results of four urinary iodine standard materials were all within the given value range and the relative deviations(RD) were all ＜ 2.0％ at different test temperature, respectively. No significant difference was found between the results of the 16 urine samples containing high concentration of iodine determined by the new method and the current standard method (|t| =0.727, P ＞ 0.05). The table of suitable combination of As3+-Ce4+ reaction temperature and reaction time for this method was obtained(such as 20 ℃ and 33 min, 25 ℃ and 25 min,30 ℃ and 19 min, etc). Conclusions This method greatly reduces the amount of arsenic in waste, reduces pollution, saves reagents, and this method is easier to be performed with better precision and accuracy, which is suitable for measuring high concentration of iodine in urine.

Objective To transplant the umbilical cord mesenchymal stem cells(UCMSCs) derived from human umbilical cord into cisterna magna of hypoxic-ischemic encephalopathy(HIE) rat model,and to observe their survival,proliferation and differentiation in the rat brain.Methods UCMSCs were isolated from human umbilical cord of babies delivered after full-term normal cesarean section,and labeled by bromodeoxyuridine(BrdU).Pregnant rats were randomly divided into experimental group(n=6) and control group(n=1).HIE models were built by ligating both sides of the uterine arteries of full-pregnant rats(21 days) in experimental group rats for 15 minutes.The neonatal rats in experimental group were divided into stem cells group(n=24) and PBS group(n=19) at random.The labeled UCMSCs were injected into cisterna magna of the rats in stem cells group,while PBS was injected into the rats of PBS group.In 1,2,3 and 4 weeks after transplantation,the brain tissue section slides were immunohistochemically stained with antibodies against BrdU,Nestin,neuron specific enolase(NSE) and glial fibrillary acidic protein(GFAP),and thionin.Control group with normal delivery was tested as concurrent control.Results At 1 week after transplantation,BrdU,Nestin,NSE and GFAP positive cells were found in the hippocampal dentate gyrus of the rats in stem cells group rats.The number of BrdU-positive and Nestin-positive cells increased(Pa0.05).The NSE-positive and GFAP-positive cells gradually increased from 1-4 weeks post transplantation and comparisons between groups had statistical significance(Pa

Animals ; Cattle ; China ; epidemiology ; Echinococcosis ; epidemiology ; parasitology ; transmission ; Echinococcus granulosus ; pathogenicity ; Humans ; Seasons

Objective To study the chemical kinetics characteristics in a new revised method with low usage amount of arsenic trioxide for determining urinary iodine by arsenite-ceric catalytic spectrophotometry using ammonium persulfate digestion,and to study the impact of operating bias in arsenite-ceric reaction temperature and reaction time on final results in this method.Methods The absorbances (A) of arsenite-ceric reaction of iodine standard series were measured at different reaction temperature and time,and the results were analyzed according to the chemical kinetics equation.The change values and half-life of A values of the new revised method and the current standard method were calculated.The chemical kinetics model of reaction system for this new revised method was deduced from experimental results.The calculation formula of result relative error for urinary iodine determination was deduced based on constants reaction temperature and reaction time and reaction rate constant factor.The result relative errors caused by operation deviation of reaction temperature or reaction time in the determination of urinary iodine were calculated.Results The usage amount of arsenious acid solution in the new revised method was only a quarter of usage amount of the current standard method(WS/T 107-2006).A values of each concentration of standard curve series at different reaction time t were obtained,the lnA to t mapping was a straight line,the linear correlation coefficients were-0.9995--0.9999.These results were in accord with the characteristic of chemical first-order reaction.Relationships between the reaction rate constant K and the reaction temperature T in the temperature range of 20-35 ℃ were well accord with Arrhenius equation.The A values and iodine concentrations (C) at various experimental temperatures showed good C =a + blnA linear relation,the absolute value of the linear correlation coefficient(｜ r ｜) ＞ 0.9990.After calculation and comparison of changes in the half-life of A values in the new revised method and in the original standard method at 20,25,30,35 ℃ reaction temperature,half-life of A values of 0-300 μg/L iodine standard series in the new revised method and in the original standard method were 191.0-11.4 min and 66.8-10.2 min at 25℃,respectively.Under the same conditions of 25 ℃ for 40 min,the gradient of A values of 0-300 μg/L iodine standard curve in the new revised method was similar to that of the original standard method(slope-133.7,-139.2,respectively).But differences between A values of standard curve and the reaction initial absorbance(A0) in the original standard method were 1.4 to 3.7 times those of the new revised method.A chemical kinetics model of reacting system for this method was established.A series of urinary iodine results relative error data were obtained when reaction temperature deviation was ± 1,± 0.5,± 0.3 ℃ or reaction time deviation was ± 1 min for sample test tubes.Data showed that relative errors of urinary iodine results caused by reaction temperature deviation or reaction time deviation in the new revised method were less than those of the original standard method.Conclusions The iodine-catalyzed arsenite-ceric reaction in the new revised method is a first-order reaction,when measuring 0-300 μg/L urinary iodine at 20-35 ℃,and 300-1200 μg/L urinary iodine at 20-30 ℃,the calibration relation of C =a + blnA is established when arsenite-ceric catalytic spectrophotometry is kept at a certain stable temperature and in certain stable reaction time.Compared with the original standard method,using the revised method with low usage amount of arsenic trioxide for measuring urinary iodine,the arsenite-ceric reaction rate is slow down.As a result,this method is easier to operate and has better precision and accuracy.

Objective:To prepare a kind of G418 resistance fibroblast feeder layers.Methods: In order to prepare a stock primary embryonic fibroblast (EMFI) cells, the pregnant Smad3ex8+/- mice containing heterozygous neo gene were killed 14 days after coitus to get the embryo. EMFI cells were tested by PCR to identify their gene types. Only one EMFI cell which contained heterozygous neo gene was chosen and treated with mitomycin C.The mitomycin C-treated EMFI feeders were stored at -70℃. Results: The EMFI feeder layers could support the growth of embryonic stem cell line TC-1 efficiently and could live in G418 resistance medium for 1-2 weeks.

Objective To investigate the effects of ciyelosporine-A(CsA).a calcinenrin(CAN)inhibitor,on electrophysiological propertiesof atria in canine tachycardia-induced model of AF.Methods Eighteen healthy adult mongrel canines weighing 17.0 to 23.2 kg(rangedfrom 2 to 4 years old)were randomized to 3 groups,Sham group(no pacemaker was implanted),atrial tachypacing group(ATP group)each group at baseline and after 8 weeks' tachypacing.Measurements included atrial effective refractory period(AERP),conductionvelocity(CV),wave length(WE),atrial fibrillation load and rate-adaptability. Results After 8 weeks' atrial tachypacing,ATP andCsA groups showed significant longer duration of the P wave,shorter AERP,decreased adaptation of AERE slower CV,shorter Wland longer AF duration compared to the shamg roup (all P＜0.05).AERP of the CsA group was longer than that of ATP group (P＜0.05),but there were no differences in rate-adaptability,CV,incidence of induced AF and AF duration between CsA group and ATP group.Conclusions Our results suggest that calcineurin pathway intervention by CsA have a positive effect on tachycardia-inducedelectrical remodeling of atria,but can not prevent or reverse AF.