[Discovery of cytochrome P450 enzymes-inhibiting components in traditional Chinese medicine].

With the widespread use of traditional Chinese medicine(TCM) and the integration of TCM and western medicine, drug-drug interaction(DDI) is considered as a major cause of therapeutic failures and side effects. Cytochrome P450 enzymes(CYPs) are responsible for large number of drug metabolism. CYP3 A4 and CYP2 D6, two important CYP isoforms, are responsible for about 80% drug metabolism of CYPs super family. The inhibition of CYPs is likely to be the most common factor leading to adverse DDI. Therefore, it is of great significance to predict potential CYP3 A4 and CYP2 D6 inhibitors to prevent the DDI. A fast and low-cost me-thod for calculating and predicting CYP inhibiting components was established in this paper, namely support vector machine(SVM) and molecular docking technology which are used to predict and screen drugs. Firstly, 12 qualitative models of two targets were established by using SVM, and the optimal model was selected to predict the compounds in traditional Chinese medicine database(TCMD). Then, molecular docking technology was used to establish docking model. By analyzing the key amino acids involved in drug-target interactions and combining with SVM model, potential inhibitors of CYP3 A4 and CYP2 D6 were found. From the computational results, astin D and epiberberine exhibited inhibition effect on CYP3 A4 and CYP2 D6, respectively. Astin D was only found in astins family from Aster tataricus, while epiberberine was considered to be the active constituent of Coptidis Rhizoma. Therefore, for the risk of DDI, extra attention should be paid to the source of these potential inhibitors, Asteris Radix et Rhizoma and Coptidis Rhizoma. This computational method provides technical support for discovering potential natural inhibitors of CYPs from Chinese herbs by using SVM and molecular docking model, and it is also helpful to recognize the CYPs-mediated DDI existing in TCM, providing research ideas for further pharmacovigilance of integrated therapy.

[NIR Assignment of Magnolol by 2D-COS Technology and Model Application Huoxiangzhengqi Oral Liduid].

Near infrared (NIR) spectroscopy assignment of Magnolol was performed using deuterated chloroform solvent and two-dimensional correlation spectroscopy (2D-COS) technology. According to the synchronous spectra of deuterated chloroform solvent and Magnolol, 1365~1455, 1600~1720, 2000~2181 and 2275~2465 nm were the characteristic absorption of Magnolol. Connected with the structure of Magnolol, 1440 nm was the stretching vibration of phenolic group O-H, 1679 nm was the stretching vibration of aryl and methyl which connected with aryl, 2117, 2304, 2339 and 2370 nm were the combination of the stretching vibration, bending vibration and deformation vibration for aryl C-H, 2445 nm were the bending vibration of methyl which linked with aryl group, these bands attribut to the characteristics of Magnolol. Huoxiangzhengqi Oral Liduid was adopted to study the Magnolol, the characteristic band by spectral assignment and the band by interval Partial Least Squares (iPLS) and Synergy interval Partial Least Squares (SiPLS) were used to establish Partial Least Squares (PLS) quantitative model, the coefficient of determination Rcal(2) and Rpre(2) were greater than 0.99, the Root Mean of Square Error of Calibration (RM-SEC), Root Mean of Square Error of Cross Validation (RMSECV) and Root Mean of Square Error of Prediction (RMSEP) were very small. It indicated that the characteristic band by spectral assignment has the same results with the Chemometrics in PLS model. It provided a reference for NIR spectral assignment of chemical compositions in Chinese Materia Medica, and the band filters of NIR were interpreted.

[Rapid assessment of critical quality attributes of Chinese materia medica (II): strategy of NIR assignment].

The present paper firstly reviewed the research progress and main methods of NIR spectral assignment coupled with our research results. Principal component analysis was focused on characteristic signal extraction to reflect spectral differences. Partial least squares method was concerned with variable selection to discover characteristic absorption band. Two-dimensional correlation spectroscopy was mainly adopted for spectral assignment. Autocorrelation peaks were obtained from spectral changes, which were disturbed by external factors, such as concentration, temperature and pressure. Density functional theory was used to calculate energy from substance structure to establish the relationship between molecular energy and spectra change. Based on the above reviewed method, taking a NIR spectral assignment of chlorogenic acid as example, a reliable spectral assignment for critical quality attributes of Chinese materia medica (CMM) was established using deuterium technology and spectral variable selection. The result demonstrated the assignment consistency according to spectral features of different concentrations of chlorogenic acid and variable selection region of online NIR model in extract process. Although spectral assignment was initial using an active pharmaceutical ingredient, it is meaningful to look forward to the futurity of the complex components in CMM. Therefore, it provided methodology for NIR spectral assignment of critical quality attributes in CMM.

High thermoelectric performance realized in a BiCuSeO system by improving carrier mobility through 3D modulation doping.

We report a greatly enhanced thermoelectric performance in a BiCuSeO system, realized by improving carrier mobility through modulation doping. The heterostructures of the modulation doped sample make charge carriers transport preferentially in the low carrier concentration area, which increases carrier mobility by a factor of 2 while maintaining the carrier concentration similar to that in the uniformly doped sample. The improved electrical conductivity and retained Seebeck coefficient synergistically lead to a broad, high power factor ranging from 5 to 10 µW cm(-1) K(-2). Coupling the extraordinarily high power factor with the extremely low thermal conductivity of ∼0.25 W m(-1) K(-1) at 923 K, a high ZT ≈ 1.4 is achieved in a BiCuSeO system.

[Multivariate detection limits of baicalin in qingkailing injection based on four NIR spectrometer types].

Multivariate detection limits (MDLs) of different types of near-infrared instruments were investigated to guide the selection of device type for TCM NIR analysis. In this paper, near-infrared spectroscopy of Qingkailing injection was performed in transmission mode on four near-infrared spectrometers named a, b, c and d, respectively. High performance liquid chromatography (HPLC) was used as the reference method to determine the content of baicalin in Qingkailing injection. Partial least squares (PLS) and interval partial least squares (iPLS) quantitative models of baicalin in Qingkailing injection were established and MDLs of quantitative models based on different types of instruments were calculated. The determination coefficient of prediction (R2(pre))and the root mean square errors of prediction (SEP) of PLS models of four different near-infrared spectrometers are 0.9762 and 230.4 microg x mL(-1) (a), 0.9561 and 246.4 microg x mL(-1) (b), 0.9662 and 264.4 microg x mL*-1) (c), 0.9985 and 71.5 microg x mL(-1) (d). And the model of instrument d shows a better prediction performance than the other three types. There are no remarkable superiorities in predictability in iPLS models of instruments a and b after variable selection, since the R2(pre) and SEP values for instruments a and b are 0.9771 and 218.4 microg x mL(-1), and 0.9754 and 219.4 microg x mL(-1), respectively. Models c and d show no results of variable selection. MDLs (delta(0.05, 0.05) of different instruments are all less than 250 microg x mL(-1), and the MDLs of instruments c and d reach to 58 and 2.9 microg x mL(-1) respectively. The results reveal that the predictability of models and corresponding MDLs are different for different detection equipments. This paper innovatively used the theory of MDL to investigate the detection performance of different types of NIR instruments. The results demonstrated the feasibility of the approach. And it is expected that in actual applications, choosing the right type of instrument should be based on the characteristics of the study carrier to ensure quantitative accuracy.

Enhanced thermoelectric performance of a BiCuSeO system via band gap tuning.

Upon 20% Te substitution, the band gap decreases from 0.8 eV to 0.65 eV. Rising temperature promotes minority carrier jumps across the band gap, thereby improving electrical conductivity. With low thermal conductivity and large Seebeck coefficients, a remarkable ZT of 0.71 at 873 K is achieved for BiCuSe0.94Te0.06O.

Adding vancomycin to bone cement: research on its influence on mechanical and fixation strength using rabbit femoral prostheses.

OBJECTIVE: To compare the influence of different methods of adding vancomycin on the strength of bone cement used for fixing rabbits' femoral prostheses. METHODS: Eighteen New Zealand white rabbits (36 femora) were allocated to three groups of six rabbits (12 femora) each: a control group, an experimental group 1 and experimental group 2. The bone cement used in the control group was mixed manually without vancomycin; in experimental group 1 it was mixed manually with 5% (2 g/40 g) vancomycin; and in experimental group 2 it was mixed in a vacuum with 5% (2 g/40 g) vancomycin. The cement combinations were then used to fill the marrow cavity of rabbit femurs to fix prostheses. An electronic universal testing machine (EUTM) was used to test the pullout force of the prostheses with bone cement 48 hours later. Student's paired t-test was used for statistical analysis. RESULTS: It was found that the maximum load of pullout force was 559.3 ± 82.3 N in the control group; 523.6 ± 86.5 N in experimental group 1; and 645.1 ± 105.9 N in experimental group 2. Statistical analysis showed there was no significant difference between the control group and experimental group 1 (P > 0.05). However, there were significant differences between the control group and experimental group 2 (P < 0.05); and between experimental group 1 and experimental group 2 (P < 0.05). CONCLUSION: When bone cement and vancomycin were mixed manually in a low concentration (<5%) vancomycin had no influence on the strength of the bone cement. However, bone cement and vancomycin mixed at the same concentrations in a vacuum did have a statistically significant effect on the strength of the bone cement.