Objective To establish a novel method for the determination of betaine in serum by high performance liquid chromatography with UV detection.Methods Pre-column derivatization of serum was performed directly in acetonitrile without extraction with p-bromophenacyl bromide and 18-crown-6 ether as catalyst.The p-bromophenacyl ester derivatives were then separated by Supelcosil LC-SCX, using an was 0.8 ml/min and the effluent was monitored at 259 nm. Betaine was used for preparation of standard curve and quantification with external standards.Results The linearity of this method was 6.25-200.00 μmol/L,the regression was 0.999 8.The detection limit was 3.0 μmol/L.The within-day imprecision was 1.88%-3.79% ( average 3.24% ), the between-day imprecision was 3.14%-6.76% ( average 4.39% ), the recovery rates were 95.89%-102.86% (average 99.16% ).Conclusion This method is sensitive, rapid, accurate and suitable for the research and routine clinical practice.

Objective To investigate the effect of diabetes on the expression of the glucose transporter (GLUT-1) in blood brain barrier (BBB) endothelial cell at different time points. Methods Forty male SD rats were randomly divided into normal control and diabetic group. Diabetic model of SD rats was established by intravenous streptozotocin(50 mg/kg) injection. Ten rats in each group were sacrificed on the 2nd month and 10th month respectively. The rat' s prefrontal cortex was removed to observe the expression of GLUT-1 in BBB EC with immunohistochemical(IHC) staining. Results By IHC method, the number of GLUT-1 positive microvessels was significantly decreased in diabetic group in the 2nd month (4. 3 ± 0. 9) compared with that of control group (6.4 ± 1.7, t = 7. 586, P < 0. 01 ) ; the number of GLUT-1 positive microvessels was significantly increased in the diabetic group in the 10th month (8.4 ± 1.4) compared with that of control group (5. 8 ± 1.7, t = 15.922,P < 0. 01 ). Conclusions Short-term diabetes GLUT-1 expression in BBB EC is downregulated in early stage, while it is upregulated in advanced stage.

The gold hollow nanospheres have been synthesized by sacrificE-template method and the obtained sample has been characterized by TEM, SEM and XRD. The amperometric formaldehyde gas sensor was assembled with gold hollow nanospheres as the active electrode material and 1 mol/L KOH solution as electrolyte. The equation of linear regression(y=16.63x+4.063×10-7, r=0.9989)between the oxidation current(y(A))and the concentration of formaldehyde(x/(mol/L)) was obtained at the formaldehyde concentration in the range of 0 to 2.23×10-6 mol/L. The sensitivity of the sensor with gold hollow nanospheres as active material increased by about 70% compared with the sensor made of nanoparticles which had the same gold-loading in the work electrode, this method exhibits an advantage of decrease in the cost of the noble metal. This kind of sensor shows potential application in formaldehyde gas detection in this range due to its excellent sensitivity, stable response and good linear relationship.

Objective To explore determinants of functional tricuspid regurgitation with twodimensional (2D) and three-dimensional (3D) echocardiography,and to provide theoretical basis for surgery treatments.Methods Fifty-six subjects with left-sided valular diseases and tricuspid regurgitation underwent 2D and 3D echocardiography examinations.The tricuspid annulus diameter,the valvular tethering height and right ventricular volume and ejection fraction were measured.Results Based on the degree of tricuspid regurgitation,the patients were grouped into mild regurgitation (group 1) and moderate or more regurgitation (group 2).Comparing the two groups by t test,the tricuspid annulus diameter,the largest distance of tricuspid valvular tethering and the end-diastolic right ventricle volume had significantly enlarged in group 2 ( P ＜0.01 ).And the degrees of tricuspid regurgitation had good correlations with the annulus diameter,the valvular tethering,the right ventricular volume and pulmonary artery systolic pressure.Also,the 3D echocardiography revealed there were some valvular pathologies aggravating regurgitation.Conclusions The degree of functional tricuspid regurgitation is mainly determined by the annulus dilation and pulmonary hypertension.Further more,the 3D echocardiography can give us more details of the valves.