64-Slice spiral double-low CT to evaluate the degree of stenosis and plaque composition in diagnosing coronary artery disease.

This study examined the application of 64-slice spiral double-low computed tomography (CT) to evaluate the degree of coronary artery stenosis. We examined 45 patients with coronary heart disease by 64-slice spiral double-low CT and coronary angiography (CAG) to determine CT accuracy in evaluating coronary artery stenosis. Imaging analysis from 64-slice spiral double-low CT identified 199 segments with coronary stenosis from 45 patients, including 46 segments with mild stenosis, 38 with moderate stenosis and 115 with severe stenosis or artery occlusion. CT analysis agreed with CAG on the identification of the degree of stenosis in 122 segments, with an overall accuracy of 61.3%. The accuracy for serious stenosis or occlusion was the highest at 69.6%. We also found a strong correlation between coronary plaque compositions and the degree of stenosis. Correspondence analysis showed that the presence of soft plaques closely correlated with severe stenosis, whereas mixed plaques closely correlated with moderate stenosis. Overall, 64-slice spiral double-low CT imaging can effectively assess the degree of coronary artery stenosis in patients with coronary heart disease and accurately detect plaque composition. Thus, 64-slice spiral double-low CT imaging can predict the risk of coronary heart disease and the degree of coronary artery stenosis, which is helpful for early diagnosis and treatment of coronary heart disease.

Enhanced catalytic performance of a PdO catalyst prepared via a two-step method of in situ reduction-oxidation.

A supported PdO nanocatalyst prepared by a facile in situ reduction process followed by an oxidation step showed significantly enhanced activity for the removal of pollutants from natural gas vehicles. The excellent catalytic performance is mainly due to high dispersion of the uniform PdO nanoparticles generated during the novel two-step method.

Ce-Zr-La/Al2O3 prepared in a continuous stirred-tank reactor: a highly thermostable support for an efficient Rh-based three-way catalyst.

Two Ce-Zr-La/Al2O3 composite oxides, CZLA-C and CZLA-B, were synthesized using a co-precipitation method in a continuous stirred-tank reactor (CSTR) and a batch reactor (BR), respectively. Two Rh-based three-way catalysts (TWCs), Rh/CZLA-C and Rh/CZLA-B were obtained by a wet-impregnation method using the two composites as the supports. The physicochemical properties of the samples before and after thermal treatment at 1000 °C were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), H2-temperature programmed reduction (H2-TPR) and CO chemisorption. The results indicated that CZLA-C shows higher thermal stability than CZLA-B due to a sparsely-agglomerated morphology. Compared with Rh/CZLA-B, Rh/CZLA-C displayed better reducibility and higher thermal stability and exhibited significantly higher activity in the catalytic removal of the simulated gasoline vehicle exhaust emission (NO, CO and C3H8). Our work can provide a facile and economical synthesis route to advanced support materials and catalysts for exhaust emission control.

Characterization and photocatalytic property of Pd/TiO2 with the oxidation of gaseous benzene.

Increasing environmental pollution caused by the volatile organic compounds due to their toxicity is a matter of great concern. So it is crucial to develop processes which can destroy these compounds effectively. It has been found that the photocatalytic activity of TiO(2) towards the decomposition of gaseous benzene can be greatly enhanced by loading Pd on the surface of TiO(2). The results show that the optimum palladium loading is 0.25wt.%. The prepared photocatalysts were characterized by XRD, UV-vis diffuse reflectance and XPS. XRD results indicate that no peaks of Pd are detected in the 2theta region from 10 degrees to 90 degrees . Pd/TiO(2) absorbs much more light than TiO(2) in the visible light region. The XPS spectrum shows that there are Ti, O, C and Pd elements on the surface of the Pd/TiO(2), the binding energy values of Ti2p of 0.25%Pd/TiO(2) transfer to a lower value. In addition, the photocatalytic performance of 0.25%Pd/TiO(2) was investigated, the result illustrates that 0.25%Pd/TiO(2) demonstrates 2.32 times the photocatalytic activity of pure TiO(2). The reason of promotion of photocatalytic performance was discussed.

Remove cooking fume using catalytic combustion over Pt/La-Al2O3.

Five monolithic catalysts with low noble metal content were prepared by immerge method (Pt/gamma-Al2O3, Pt/La-Al2O3, Pt/YSZ-Al2O3, Pt+Pd/La-Al2O3 and Pd/La-Al2O3) and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. The Pt/La-Al2O3 catalyst has the highest activity and can be applied in wide range of gas hourly space velocity (GHSV). Some characterizations (XRD, TPR) were carried out with the objective to explain differences in catalytic behaviors. The prepared catalyst showed a great potential for application.

[Changes in plasma levels of adrenomedullin and cyclic adenosine monophosphate and their interrelation in patients with chronic heart failure].

OBJECTIVE: To investigate the changes in plasma levels of adrenomedullin (ADM) and cyclic adenosine monophosphate (cAMP) in patients with chronic heart failure (CHF) in an attempt to understand the role of ADM in the occurrence and development of CHF. METHODS: The plasma levels of cAMP and ADM were measured by radioimmunoassay in 45 patients with CHF (including 10 of NYHA classII, 15 of class III, and 20 of class IV) and 20 healthy controls respectively. RESULTS: Plasma ADM and cAMP levels significantly increased in patients of NYHA class II, III, and IV as compared with the healthy controls (P<0.05), with those of class III patients being the highest. Positive correlation between ADM and cAMP was noted in CHF patients(r=0.735, P<0.01). CONCLUSION: Plasma levels of ADM and cAMP were in close correlation with the degree of heart failure, varying dynamically with the development of heart failure. There was mutual accommodation between ADM and cAMP, and increased cAMP level partly results from elevated ADM level in CHF patients.