The Effect of Sulfonated Graphene on the Rheological Properties of Cement Paste.

With unique 2D nanostructures and excellent properties, graphene and its derivatives are a class of advanced nanosized reinforcements for cementitious materials. Sulfonated graphene (SG), one of the most important modified graphene materials, possesses sulfonate groups on the surface and significantly improves the mechanical and thermal properties of cement-based composites. It is important to investigate the influence of SG on cement-based materials as it is a prerequisite for practical applications. Herein, SG was prepared and introduced into cement paste to investigate its influence on the rheological properties of cement paste. With the increased addition of SG, a stable slurry was gradually obtained with low fluidity and high rheological parameters. The mechanism of the SG effect on the rheological properties of cement paste was also illustrated. Because of the high specific surface area and sulfonate groups of SG nanosheets, a large amount of flocculated structure was created by the complexing effect, chemical interaction, physical interaction and mechanical interlocking between SG and hydrated/unhydrated cement particles. Furthermore, polycarboxylate ether (PCE) superplasticizer was introduced to ensure fluidity and transportability in the practical application of SG. The results in this work lay a foundation for the practical application of modified graphene in cementitious materials.

[Comparison of benazepril monotherapy to amlodipine plus benazepril in the treatment of patients with mild and moderate hypertension: a multicentre, randomized, double-blind, parallel-controlled study].

OBJECTIVE: To evaluate the efficacy and tolerability of the fixed combination of amlodipine 5 mg/benazepril 10 mg once-daily therapy, compared with benazepril, 10 mg, monotherapy in patients with mild and moderate hypertension, and to evaluate the 24 h antihypertensive efficacy and the duration of action by ambulatory blood pressure monitoring. METHODS: In a multicenter, randomized, double-blind, parallel controlled trial, 356 cases of hypertensive patients after 2 weeks wash-out, and then given 4 weeks of benazepril 10 mg monotherapy, 220 patients with mean seated diastolic blood pressure (SeDBP) remained ≥ 90 mm Hg (1 mm Hg = 0.133 kPa) were randomly divided into benazepril 10 mg/amlodipine 5 mg (BZ10/AML5) fixed-dose combination therapy group (once a day, n = 113), and benazepril monotherapy group (daily 20 mg, n = 107). In the two groups the patients with SeDBP ≥ 90 mm Hg were doubled the dosage of the initial regimen at the end of 4-week treatment for additional 4 weeks, and the patients with SeDBP < 90 mm Hg remained the initial regimen for additional 4 weeks. The primary endpoint was to evaluate the improvement of SeDBP at the end of 8-week treatment. There were 74 patients (the combination therapy group n = 38, monotherapy therapy group n = 36) completed the 24 h ambulatory blood pressure monitoring which was included in the final efficacy analysis. RESULTS: The randomized, double-blind treatment for 8 weeks, the mean value of SeDBP reduction, the reaching target blood pressure rate and total successful response rate to the treatment (a SeDBP < 90 mm Hg or a decrease of 10 mm Hg or more from baseline) were (11.7 ± 6.8) mm Hg, 65.7% and 88.5% in the combination therapy group, respectively, and were (7.7 ± 6.9) mm Hg, 35.5% and 65.5% in the monotherapy group, respectively. There were statistically significant difference between the combination therapy and the monotherapy groups in all the 3 indexs (P < 0.001). The fixed combination significantly reduced systolic blood pressure (SBP) and diastolic blood pressure (DBP) values throughout the 24 h. The trough to peak ratios of DBP/SBP in the fixed compound of benazepril/amlodipine (10 mg/5 mg) and benazepril (20 mg) alone were 83.1%/76.0% and 85.8%/79.5%, respectively. Adverse events rates were 16.8% in the combination therapy group and 35.5% in the monotherapy group (P < 0.001). CONCLUSIONS: The combination therapy with benazepril/amlodipine was superior to benazepril monotherapy and was well tolerated in patients with essential hypertension and allowing a satisfactory BP control for 24 hours.

[Determination of cichoric acid in Echinacea purpuea].

OBJECTIVE: To analyze the natural change rule of active components of E. purpuea by measuring content of cichoric acid. METHOD: Reverse HPLC method was used. RESULT: The maximum cichoric acid content of the roots occured in seedling age of May, and that of the flowers occured in blooming stage of mid July, but cichoric acid in stems was generally low anyway. The maximum content of cichoric acid in the plant above ground occured in the blooming stage of mid July. CONCLUSION: The measuring method of content of cichoric acid is successful and reliable. The optimum stage of harvest in Echinacea purpuea should be guided by natural change rule of cichoric acid content.