This paper was aimed to study the quantitation method of bitterness intensity of bitter drug, and to ex-plore the mutual relations between the bitterness intensity and the concentration of bitter drugs solution. The mod-el drug of berberine hydrochloride, which was made into a series of solutions of different concentrations, was ap-plied. Twenty volunteers, who were screened, trained and qualified, tasted the different concentration of aqueous solution, with the purpose of detecting the rank bitterness intensity. After analyzing the features of the data and testing the logarithm model and Weibull curve model, as well as nonlinear fitting, we finally set up the appropri-ate relationship curve between the concentration and the bitterness intensity. There is a good curve positive corre-lation between the bitterness intensity and the concentration, which is consistent with the Weibull curve model (R2= 0.9973, RMSE = 0.0976, RMSECV = 0.1453). The fitting degree of the model established in this paper is high, which provides a reference for quantitation and forecast of the drug bitterness.

Taste-masking effect of pharmaceutical formulation is important for the pharmacy worker to carry out study on taste-masking of pharmaceutical formulation. This study discussed the feasibility of electronic tongue in the evaluation of taste-masking effect. The berberine hydrochloride was used as model drug of bitterness. Sodium cycla-mate, 2,4-Dihydroxybenzoic acid and sodium cyclamate were used as bitterness inhibitors. Through detection of elec-tronic tongue, results from principal component analysis (PCA), and indexes such as distance of bitterness (D), dis-tance of bitterness reduction, inhibition rate (Ir), the determination was given on whether results from the bitterness inhibition of berberine hydrochloride and taste results from volunteers were the same. In addition, sodium cyclamate, which was the best bitterness inhibition, was made into different concentrations in order to optimize its using dosage. The data analysis results showed that in the berberine hydrochloride solution with the concentration of 0.005 mg/mL, the ranking order of the bitterness-masking efficiency was sodium cyclamate > 2,4-Dihydroxybenzoic acid > sodium acetate anhydrous. Along with the increasing concentration of sodium cyclamate, the taste-masking effect is better. However, after the concentration level of 0.2%, the change on taste-masking effect was relatively small. In the prac-tical work, the concentration of sodium cyclamate can be selected at the level of 0.2%. This experiment effect was the same as the human taste results. This study showed that the electronic tongue may be a useful tool in the evalua-tion of taste-masking efficiency to some extent.

To examine the association between serum copper concentration and the prevalence of hypertension in patients with knee osteoarthritis (OA).
 Methods: A total of 935 patients who were aged ≥40 years and underwent routine checkups from October 2013 to November 2014 at the Health Management Center of Xiangya Hospital, Central South University were included. They were diagnosed as knee OA by weight-bearing bilateral anteroposterior radiography. Serum copper concentration was measured using the chemiluminescence method. Blood pressure was measured by an electronic sphygmomanometer. The association between serum copper concentration and hypertension was evaluated by conducting multivariable adjusted logistic regression.
 Results: Compared with the lowest quintile, the multivariable-adjusted odds ratio (OR) and related 95% confidence interval (95% CI) of hypertension were 1.46 (95% CI 1.02 to 2.09, P for trend=0.035) and 1.47 (95% CI 0.77 to 2.78, P for trend=0.032) in the total population and female subgroup of the highestest quintile, respectively. There was no significant association between serum copper and hypertension in male subgroup among OA patients (OR=1.21, 95% CI 0.76 to 1.93, P for trend=0.354).
 Conclusion: The serum copper concentration was significantly associated with the prevalence of hypertension in total population and female subgroup, but may not in male subgroup among patients with knee OA.
Adult ; Copper ; Cross-Sectional Studies ; Female ; Humans ; Hypertension ; complications ; Male ; Odds Ratio ; Osteoarthritis, Knee ; complications ; Risk Factors

l-cysteine is an important sulfur-containing α-amino acid. It exhibits multiple physiological functions with diverse applications in pharmaceutical cosmetics and food industry. Here, a strategy of coordinated gene expression between carbon and sulfur modules in Escherichia coli was proposed and conducted for the production of l-cysteine. Initially, the titer of l-cysteine was improved to (0.38±0.02) g/L from zero by enhancing the biosynthesis of l-serine module (serA^f, serB and serC^Cg) and overexpression of CysB. Then, promotion of l-cysteine transporter, increased assimilation of sulfur, reduction or deletion of l-cysteine and l-serine degradation pathway and enhanced expression of cysE^f (encoding serine acetyltransferase) and cysB^St (encoding transcriptional dual regulator CysB) were achieved, resulting in an improved l-cysteine titer (3.82±0.01) g/L. Subsequently, expressions of cysM, nrdH, cysK and cysIJ genes that were involved in sulfur module were regulated synergistically with carbon module combined with utilization of sulfate and thiosulfate, resulting in a strain producing (4.17±0.07) g/L l-cysteine in flask shake and (11.94±0.1) g/L l-cysteine in 2 L bioreactor. Our results indicated that efficient biosynthesis of l-cysteine could be achieved by a proportional supply of sulfur and carbon in vivo. This study would facilitate the commercial bioproduction of l-cysteine.
Escherichia coli/metabolism* ; Cysteine/metabolism* ; Bioreactors ; Sulfur/metabolism* ; Serine/metabolism*

OBJECTIVE: To establish a method for determination of N-methyl-2-pyrrolidone(NMP) in workplace air by solvent desorption-gas chromatography. METHODS: NMP in the workplace air was collected with activated carbon tube and desorbed with methanol ∶dichloromethane(5 ∶95, V/V). After desorption, it was separated by capillary column separation, and detected by flame ionization detector. RESULTS: The good linear concentration of NMP was 0.51-4 108.00 mg/L. The correlation coefficient was 0.999 9. The detection limit was 0.08 mg/L(calculated by 3 times of standard deviation). The average desorption efficiency was 101.68%-103.44%. The within-run and between-run relative standard deviations were 1.94%-3.97% and 0.97%-2.26%, respectively. The sample could be stored at room temperature for at least 14 days. CONCLUSION: The developed method is suitable for the determination of NMP in workplace air.