A New Determination Method of the Solubility Parameter of Polymer Based on AIE.

An accurate method of the fluorescence probe approach based on an aggregation-induced emission (AIE) molecule (tetraphenylethylene) for measuring the solubility parameter of the polymer is reported. This method is distinctive in that the approach can make the polymer chain conformation in solution be related to the fluorescence intensity. Since the solubility parameter of the polymer is also closely linked to its chain conformation in solution, the solubility parameter can be determined by the fluorescence intensity. The range of the solubility parameter of polymethyl methacrylate (PMMA) tested by this method was from 9.00 cal1/2cm-3/2 to 10.00 cal1/2cm-3/2. The results are more accurate than those obtained from the traditional turbidimetric titration method, ranging from 8.60 cal1/2cm-3/2 to 12.15 cal1/2cm-3/2. According to the photoluminescence (PL) intensities spectra, the solubility parameters of PMMA and polyvinyl acetate (PVAc) are 9.19 cal1/2cm-3/2 and 9.85 cal1/2cm-3/2, respectively.

Determination of the content of residual solvents in Haikesu I by head-space gas chromatography.

OBJECTIVE: To explore the usefulness of head-space gas chromatography for the determination of methanol and ethanol in Haikesu I,a raw material of artificial musk. METHODS: The determination was performed on HP-5(30 m×0.53 mm,5 Μm)capillary column with an hydrogen flame ionization detector. The solvent was dimethyl sulfoxide and the internal standard was acetone. The injector temperature and the detector temperature were controlled at 180 ℃ and 250 ℃,respectively. The carrier gas was nitrogen. The containers of head-space injector were preheated at 90 ℃ for 15 minutes. The column temperature was programmed raised,which achieved baseline separation of the components. RESULTS: The results showed a good linear relationship for methanol and ethanol in their linearity range;and the limit of detection was 0.8 and 1.0 Μg/ml,respectively. The precision and average recoveries were satisfactory. CONCLUSION: The head-space gas chromatography is simple,rapid,and precise technique for the measurement of residual solvents in Haikesu I.

Determination of the content of residual solvents in Haikesu 2 by head-space gas chromatography.

OBJECTIVE: To determine ethylacetate and petroleum ether(60-90 ℃)in Haikesu 2,which is one of the raw materials of artificial musk,using the head-space gas chromatography. METHODS: The determination was performed on HP-5(30 m×0.53 mm,5 Μm)capillary column with an hydrogen flame ionization detector. The solvent was dimethyl sulfoxide and the internal standard was methanol. The injector temperature and the detector temperature were controlled at 180 ℃ and 250 ℃,respectively. The carrier gas was nitrogen. The containers of head-space injector were preheated at 90 ℃ for 15 minutes. The column temperature was programmed raised,which achieved baseline separation of the components. RESULTS: The results showed a good linear relationship for ethylacetate and petroleum ether(60-90 ℃)in their linearity range;and the limit of detection was 0.7 and 0.3 Μg/ml,respectively. The good precision and good average recoveries were satisfactory. CONCLUSION: The head-space gas chromatography is simple,rapid,and precise technique for the measurement of residual solvents in Haikesu 2.

Determination of the content of residual solvents in muscone by head-space gas chromatography.

OBJECTIVE: To explore the usefulness of a head-space gas chromatography in the determination of residual solvents including methanol,ethanol,ethyl ether,and petroleum ether in muscone in artificial musk. METHODS: The head-space gas chromatography was performed on HP-5(30 m×0.53 mm,5 Μm)capillary column with a hydrogen flame ionization detector. The carrier gas was nitrogen and the solvent was dimethyl sulfoxide. The injector temperature and the detector temperature were controlled at 180 ℃ and 250 ℃,respectively. The containers of head-space injector were preheated at 80 ℃ for 15 minutes. The column temperature was programmed raised,which achieved baseline separation of the components. RESULTS: The results showed a good linear relationship for methanol,ethanol,ethyl ether,and petroleum ether(60-90 ℃)in the range of each consistency; and the limit of detection was 0.8,1.0,0.1,and 0.3 Μg/ml,respectively. The precision and average recoveries were satisfactory. CONCLUSION: The head-space gas chromatography is simple,rapid,and precise technique for measuring residual solvents in muscone.

[Study on the global and local calibration methods of tryptophan content in rice by near infrared reflectance spectroscopy].

Tryptophan is one of the essential amino acids in human, and also considered as an important limiting amino acid in rice. Alkali hydrolysis method was used to determine the tryptophan content of 272 representative samples selected from the 1 256 samples in four years. Based on the milled rice flour spectroscopy, by comparing the prediction abilities of the equations with global calibrations and local calibration, the global calibration method with MPLS and the local calibration method were better than others. Their calibration models could be introduced to application because of low standard errors of prediction for both methods (0.007%) and high coefficients of determination (87.1% and 87.4%, respectively). Furthermore, the prediction ability of the equation based on the brown rice spectroscopy could be still used for determination application though their effects were worse than that of the milled rice flour spectroscopy. It was concluded that the equation could be directly used to estimate the content of tryptophan in milled rice, and the technology of near infrared reflectance spectroscopy developed in this study could be applied in selecting breeding materials for higher tryptophan content and in quality control during rice processing.

Method for umbilical cord blood-derived basophils by FCM.

We have devised a method for the purification of human basophils from umbilical cord blood by FCM. Umbilical cord blood was collected from six healthy, full-term deliveries. After separation of red blood cells, mononuclear cells were isolated by Ficoll-Hypaque. Six samples followed by positive selection using flowcytometry (FCM) for CD203c(+)CD45(int+) cells. Purity and recovery of cells were measured. Purity and recovery of basophils by FCM with CD203c(+)CD45(int+) markers were 95.02 +/- 2.94% and 61.42 +/- 5.95%. Cell sorting for CD203c(+)CD45(int+) cells by FCM is an improved method for obtaining pure umbilical cord blood-derived basophils. We established cord blood-derived basophil purification technique as a source from which active basophils can be isolated for immunochemical characterization.

[Ionizing radiation-regulated killing of human hepatoma cells by liposome-mediated CDglyTK gene delivery].

EGR-1 gene promoter and CDglyTK gene were used to construct the pcDNA3-EGR-CDglyTK recombinant vector, in which CDglyTK gene expression was under the control of EGR-1 gene promoter. Cationic liposome LipofectAMINE was used to transfect plasmids into human hepatoma 7402 cell line. Subsequently, the transfected cells were treated with different doses of gamma-ray. Northern blot and Western blot showed that ionizing radiation can induce CDglyTK gene expression drived by EGR-1 promoter,in a dose-dependant manner. There was no ionizing radiation-inducible effect in pcDNA3-CMV-CDglyTK control group. Ionizing radiation also markedly enhanced the sensitivity of tumor cells transfected with pcDNA3-EGR-CDglyTK to prodrugs (GCV/5-FC) in tumor cell killing. The data indicated that EGR-1 promoter was inducible by ionizing radiation, whereas the CMV promoter was not. There was a synergetic effect between GCV and 5-FC. The cytotoxic effect of the suicide gene-ionizing radiation combination was stronger than suicide gene alone or ionizing radiation alone.

A sensitive optode membrane for berberine using conjugated polymer as sensing material.

A new optode membrane for the sensitive determination of berberine based on fluorescence quenching of a conjugated polymer, poly(2,5-dimethoxy-phenyldiacetylene) (PDPA), is proposed. Incorporated in a membrane composed of plasticized poly(vinyl chloride) (PVC), the conjugated polymer exhibits better stability than those small sensing molecules regarding its excellent optical properties and lipophilic characteristics. Moreover, upon the introduction of a negatively charged lipophilic additive (tetraphenylborate salt) into a PVC membrane, the optode displayed enhanced sensitivity. In addition, satisfactory analytical sensing characteristics for determining beberine were obtained in terms of the selectivity, reversibility and reproducibility with a detecting range of between 7.5 x 10(-7) mol l(-1) and 7.5 x 10(-4) mol l(-1). The optode membrane has been applied to determine berberine in commercial tablets. The results showed a good agreement with those obtained by the pharmacopoeial method.

A selective PVC membrane for di- or trinitrophenol based on N,N-dibenzyl-3,3',5,5'-tetramethylbenzidine.

A new fluorophore, N,N-dibenzyl-3,3',5,5'-tetramethylbenzidine (NBTMB), was prepared and shown to exhibit significant and analytical usefulness for optical sensing toward 2,4-dinitrophenol or 2,4,6-trinitrophenol (picric acid) when it was immobilized in a plasticized poly(vinyl chloride) (PVC) membrane. When the membrane was applied to aqueous nitrophenol solution, NBTMB was able to extract selectively nitrophenol into the membrane phase. Since the extraction equilibrium was accompanied by fluorescence quenching of NBTMB, the chemical recognition process could be directly translated into an optical signal. The sensor showed reversible response in the concentration range from 2.0 x 10(-7) to 6.0 x 10(-5) mol L(-1) for the detection of 2,4-dinitrophenol in NaOAc-HOAc buffer at pH 4.0. It also showed a fast response time (t95% < 1.5 min) when the sensor was applied to 2,4-dinitrophenol solution at concentration levels of 5.26 x 10(-6) and 2.10 x 10(-5) mol L(-1) alternatively. A working principle is proposed and the responses of this sensor to various kinds of nitrophenol were studied. The sensor was applied to the direct determination of 2,4-dinitrophenol in prepared water samples and the indirect assay of the drug cinchonine and the results obtained were satisfactory.

[Combination therapy of experimental murine hepatoma with mIL-12 gene and MHC I gene mediated by liposome].

BACKGROUND & OBJECTIVE: Interleukin-12 gene and MHC I gene have been used in gene therapy for cancer individually. To explore the synergistic antitumor effects of these two genes, the therapeutic effects of mIL-12 gene combined with MHC I (mouse H-2K) gene mediated by cationic liposome for experimental murine hepatoma were investigated. METHODS: Balb/C mouse liver cancer MM45T. Li cells were transfected with pcDNA3/mIL-12, pcDNA3/H-2Kb(H-2K of C57BL/6 mouse), and pcDNA3/GFP (reporter gene) mediated by lipofectAMINE 2000(LF 2000). The expressions of foreign genes in transfected cells were detected. Balb/C mice were inoculated subcutaneously with pcDNA3/mIL-12 and pcDNA3/H-2Kb transfected MM45T. Li. The tumorigenesis of the inoculated cells was detected. After intratumoral injection with LF2000-plasmid DNA complexes, the growth of murine tumor and the survival time of the tumor bearing mice were observated. RESULTS: The optimal ratio of LF2000: DNA is 3:1(microgram: microgram). The transfection efficiency reached to 30%. RT-PCR result showed the specific amplified fragments of the mIL-12 cDNA and H-2Kb cDNA in the transfected cells. Western blot analysis showed the expression of H-2Kb protein at 57 kDa. ELISA assay showed that the secretory mIL-12 was 48 ng/ml/10(6) cells. The tumorigenesis was decreased for transfected MM45T. Li cells with pcDNA3/mIL-12 and pcDNA3/H-2Kb. FACS assay showed that the numbers of CD3+, CD4+, and CD8+ cells from murine spleen were increased more in therapeutic group than in control group. The tumors grow slowly. The mIL-12 gene combined with H-2Kb gene has stronger antitumor effect for mouse liver cancer than single gene. CONCLUSION: The combination therapy with mIL-12 gene and MHC I gene mediated by LF-2000 have the positive synergistic antitumor effect for experimental murine hepatoma.