Purity and Uncertainty Study of CRM Betulin by DSC.

Betulin (BE) can be obtained from many plants, such as those belonging Betulaceae family, and pharmacological investigations showed its notable biological properties and good potential for food and pharmaceutical development. We investigated the homogeneity, stability, purity, and uncertainty of a newly certified reference material (CRM) of BE. The certified purity value for the CRM of BE was 99.56% with an extended uncertainty of 0.07% (k = 2, P = 0.95), as determined by differential scanning calorimetry (DSC). In this study, DSC was used for the first time for purity determination of BE. Given its high accuracy, precision, and reproducibility, DSC can be used as an alternative technique for purity determination of CRMs in the pharmaceutical and food industry.

Dual Inhibition of Topoisomerase II and Tyrosine Kinases by the Novel Bis-Fluoroquinolone Chalcone-Like Derivative HMNE3 in Human Pancreatic Cancer Cells.

Both tyrosine kinase and topoisomerase II (TopII) are important anticancer targets, and their respective inhibitors are widely used in cancer therapy. However, some combinations of anticancer drugs could exhibit mutually antagonistic actions and drug resistance, which further limit their therapeutic efficacy. Here, we report that HMNE3, a novel bis-fluoroquinolone chalcone-like derivative that targets both tyrosine kinase and TopII, induces tumor cell proliferation and growth inhibition. The viabilities of 6 different cancer cell lines treated with a range of HMNE3 doses were detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cellular apoptosis was determined using Hoechst 33258 fluorescence staining and the terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay. The expression of activated Caspase-3 was examined by immunocytochemistry. The tyrosine kinase activity was measured with a human receptor tyrosine kinase (RTK) detection kit using a horseradish peroxidase (HRP)-conjugated phosphotyrosine (pY20) antibody as the substrate. The topoisomerase II activity was measured using agarose gel electrophoresis with the DNA plasmid pBR322 as the substrate. The expression levels of the P53, Bax, Bcl-2, Caspase-3, -8, -9, p-cSrc, c-Src and topoisomerase II proteins were detected by western blot analysis. The proliferation of five of the six cancer cell lines was significantly inhibited by HMNE3 at 0.312 to 10 µmol/L in a time- and dose-dependent manner. Treatment of the Capan-1 and Panc-1 cells with 1.6 to 3.2 µM HMNE3 for 48 h significantly increased the percentage of apoptotic cells (P<0.05), and this effect was accompanied by a decrease in tyrosine kinase activity. HMNE3 potentially inhibited tyrosine kinase activity in vitro with an IC50 value of 0.64±0.34 µmol/L in Capan-1 cells and 3.1±0.86 µmol/L in Panc-1 cells. The activity of c-Src was significantly inhibited by HMNE3 in a dose- and time-dependent manner in different cellular contexts. Compared with the control group, HMNE3 induced increased expression of cellular apoptosis-related proteins. Consistent with cellular apoptosis data, a significant decrease in topoisomerase IIß activity was noted following treatment with HMNE3 for 24 h. Our data suggest that HMNE3 induced apoptosis in Capan-1 and Panc-1 cells by inhibiting the activity of both tyrosine kinases and topoisomerase II.

Dimerization and Isomerism Effects on Two-Photon Absorption of Tetraphenylethene Derivatives and Molecular Design for Two-Photon Absorption Materials.

The two-photon absorption (TPA) properties of a new tetraphenylethene derivative and its covalent dimers have been calculated employing the density functional response theory. It is found that linear arrangement of branches can give rise to a cooperative TPA behavior. Partial planarity and linear arrangement are the possible reasons for the observed aggregation-induced TPA enhancement. On the basis of the model molecule, we have designed a series of tetraphenylethene derivatives which differ by donor moieties, connection modes, or central bridges after taking the structure-property relationship of TPA mechanism into account. The TPA spectra of the designed molecules have been calculated, and their TPA properties are analyzed at length. Our results suggest that the change of the connection mode of the carbazole group and the introduction of a vinylene or ethynylene linkage into a molecule can enhance TPA intensity greatly. It can be expected that all of the designed molecules could possess high TPA features. This research is helpful for the design of efficient TPA materials.

[Genotypes of hepatitis B virus in Henan Luohe area].

OBJECTIVE: To determine the main genotype of hepatitis B virus (HBV) prevailed in Henan Luohe area. METHODS: Serum specimens were collected from 94 HBsAg positive individuals, and HBV S gene were obtained by PCR amplifying, and the gene sequences were analyzed and the polygenetic tree was drawn by the software MEGA3. RESULTS: About 75.7% samples of HBV S gene clustered in genotype C, about 20% samples clustered at genotype B in the HBV polygenetic tree, about 4.3% samples clustered at genotype D in the HBV polygenetic tree. CONCLUSION: The main genotype of hepatitis B virus prevalent in Henan Luohe is genotype C, genotype B is rarely seen, and genotype D is rarely seen.

[Field test and evaluation of landfill performance and structure with evapotranspiration cover].

Water balance performance of an evapotranspiration landfill was studied, considering vegetation structures, soil textile, and soil cover thickness. Results of six experiments showed that the transpiration process played an importance role in controlling water balance in the ET cover system. A nonlinear relationship was established between the transpiration amount and vegetation leaf area index. The evapotranspiration amount was 3.3 to 4.5 times as that of evaporation in the bare soil. In a 60 cm soil profile, the soil water storage capacities were 97.2 mm and 62.8 mm with and without a vegetation cover, respectively. Precipitation infiltration behaved preferentially and heterogeneously, and the preferential flow was the major contribution to percolation. The ratios between maximum and average infiltration depths were 3.65, 1.77, and 1.40, respectively, for 20 mm, 40 mm, and 60 mm of precipitation. Therefore, besides soil textile, soil cover thickness, and the initial water content, precipitation amount was an essential factor affecting the water storage capacity. Numerical simulated results indicated that using a sandy loam as the cover soil was more effective in removing water through evapotranspiration and reducing percolation than using a clay soil.