反相气相色谱法研究端羟基聚丁二烯粘合剂的表面性质

采用气相反相色谱技术(IGC)研究了端羟基聚丁二烯(HTPB)粘合剂的表面物理化学性质。结果表明,HTPB的色散分量随着温度的升高而降低,总表面自由能表现出与色散分量相一致的规律。与聚乙烯相比,HTPB具有更高的表面自由能,因为HTPB表面含有羟基。极性分量以及酸、碱分量随着温度的升高而逐渐增大,酸性分量比碱性分量大,且对温度更敏感、增大的更快,这表明HTPB显示较强的布伦斯特酸性。

反相气相色谱法研究缩水甘油叠氮聚醚黏合剂的表面性质

采用反相气相色谱法(IGC)研究了缩水甘油叠氮聚醚(GAP)黏合剂的表面物理化学性质。研究结果表明,GAP的色散分量随着温度的升高而降低,总表面能表现出与色散分量相一致的规律。与聚乙烯相比,GAP的总表面的自由能较高,这主要是因为GAP表面含有羟基和叠氮基团。而极性分量以及酸、碱分量,则随着温度的升高而逐渐增大,酸性分量相对碱性分量对温度更敏感、增大更快,这表明GAP显示更强的布伦斯特酸性。

Qualitative and Quantitative Analysis of Linoleic Acid in Polygonati Rhizoma

Objective To explore the major compound in Polygonati Rhizoma(Huang Jing,黄精)for quality control.Methods The major compound was isolated and analyzed by liquid chromatography-mass spectrometry(LC-MS),and subsequently further identified by nuclear magnetic resonance(NMR).Thin layer chromatography(TLC)was optimized based on the previous methods reported in the Chinese Pharmacopeia(2015 edition).Results The major compound was isolated from the natural material and identified as linoleic acid.A high performance liquid chromatography(HPLC)method with robust linearity(R2=0.9997),specificity,precision,stability,repeatability and recovery was developed for linoleic acid determination.TLC chromatogram was improved significantly after optimization for qualitative analysis.Conclusions The optimized TLC method is practical and can be adopted for quality control of Polygonati Rhizoma(Huang Jing,黄精).The levels of linoleic acid vary between species of Polygonati Rhizoma(Huang Jing,黄精),with Polygonatum cyrtonema Hua(Jiang Xing Huang Jing,姜型黄精)showing the highest contents.This study provides valuable information for quality control of Polygonati Rhizoma(Huang Jing,黄精).

5-ASA in ulcerative colitis:Improving treatment compliance

5-aminosalicylic acid(5-ASA)compounds are a highly effective treatment for ulcerative colitis(UC).While UC patient compliance in clinical studies is over 90%, only 40%of patients in every day life take their prescribed therapy.Adherence to medication has been emphasized recently by a Cochrane meta-analysis that has suggested that future trials of 5-ASA in UC should look at patient compliance rather than drug efficacy. Better compliance can be obtained by reducing the number of tablets and times of administration.Given that the 5-ASA formulations have different delivery systems that split the active moiety in various regions of the intestine,it is particularly important that an adequate dose of the drug arrives at the inflamed part of the colon.5-ASA Multi matrix(MMx)is a novel,high strength(1.2 g),oral formulation designed for oncedaily dosing.It releases the active moiety throughout the colon.Different studies with this compound have shown that it is as effective as 5-ASA enema in the treatment of mild-to-moderate,left-sided UC,and is comparable to a pH-dependent,delayed release 5-ASA (Asacol ),even if given once daily.Recently,the effectiveness in the acute phase of UC has been confirmed also in maintenance.In conclusion,at present,5-ASA MMx seems theoretically the best agent for maintaining patient compliance,and consequently,treatment effectiveness.

DTNBP1 Gene Is Associated with Some Symptom Factors of Schizophrenia in Chinese Han Nationality

Objective To study the association of DTNBP1 gene with some symptom factors of schizophrenia.Methods A total of 285 unrelated schizophrenic individuals were recruited from December 2004 to January 2009 for genetic analysis,and their symptom factors were assessed based on the Positive and Negative Syndrome Scale(PANSS).The quantitative trait test was performed by the UNPHASED program(version 3.0.12) to investigate the association between scored positive and negative symptoms and the single nucleotide polymorphisms(SNPs) in DTNBP1 gene.Results The quantitative trait test showed allelic association of rs909706 with the excitement symptom of schizophrenia(P<0.05,adjusted by 10 000 permutations),while the genotype C/G of rs2619539 with a negative symptom,lack of spontaneity and flow of conversation(P<0.05,adjusted by 10 000 permutations).Conclusion DTNBP1 variations are possibly associated with some symptoms of schizophrenia,which could partly explain the relationship between the susceptibility gene DTNBP1 and that disease.

Lysine-specific Demethylase 1 Represses THP-1 Monocyte-to-macrophage Differentiation

Objective To investigate the role of lysine-specific demethylase 1 （LSD1） in the process of THP-1 monocyte-to-macrophage differentiation. Methods Quantitative reverse transcription-polymerase chain reaction （qRT-PCR） and Western blotting were performed to analyze the expression of LSD1 and interleukin-6 （IL-6） in THP-1 monocytes and THP-l-derived macrophages. Chromatin immunoprecipitation （ChiP） assay was applied to detect the occupancy of LSD1 and H3K4 methylation at IL-6 promoter during THP-1 monocyte-to-macrophage differentiation. IL-6 mRNA level and H3K4 methylation at IL-6 promoter were analyzed using qRT-PCR and ChiP assay in LSD 1 -knockdown THP- 1 cells treated with 12-O-tetradecanoylphorbol- 13-acetate （TPA） for 0 4, 8, 12, and 24 hours. Fluorescence activated flow cytometry was performed to reveal the percentage of macrophages differentiated from THP- 1 monocytes. Results The expression of LSD1 reduced during THP-1 monocyte-to-macrophage differentiation （P〈0.01）. LSD1 occupancy decreased and H3K4 methylation increased at IL-6 promoter during the differentiation. With knockdown of LSD1, H3K4 methylation at IL-6 promoter was found increased after TPA treatment at different times points （all P〈0.05, except 24 hours）. The percentage of macrophages increased significantly in theTHP-I cells with LSD1 knockdown （P〈0.05）. Conclusions LSD1 is repressed during the monocyte-to-macrophage differentiation of THP-1 cells. Suppression of LSD 1-mediated H3K4 demethylation may be required for THP-1 monocyte-to-macrophage differentiation.

Vapor Pressures of Di-n-Butyl Phthalate and Di-iso-Butyl Hexahydrophthalate at Reduced Pressures

In this paper the measured values of the vapor pressures by ebulliometer method of two important maleic anhydride recovery solvents, di-n-butyl phthalate (DBP) and di-iso-butyl hexahydrophthalate (DIBE), between 0.63—17.79 kPa and 0.49—30.95 kPa,are reported respectively.A comparison of the data of DBP with the published data has been made, which shows good consistency. For the convenient use of these vapor pressures, Cragoe equation, Antoine equation and Kirchhoff equation are selected to correlate them. The correlating results show that Antoine equation is the best one of the three equations to fit for the vapor pressures of the two solvents. According to Clausius-Clapeyron equation, the linear relationship between natural logarithm of pressure and reciprocal of temperature is used to calculate the molar latent heats of evaporation of the two organic solvents. The molar latent heats of evaporation of DBP and DIBE are 75.1 kJ/mol and 67.7 kJ/mol, respectively.

Relationship between the Composition of Polymer of n-Alkyl Substituted Acrylate and Vinyl Amine and Their Performance on Pour Point Depression

Polymer of n-alkyl substituted acrylate （PA） with the alkyl side chains C16- 30 were synthesized. Their crystallinity, solubility and effect on pour point depression were studied. Results showed that only carbon atoms located far away from polar groups of PAL pour point depressants participated in crystallization. When the number of carbon atoms that participated in crystallization is about three fourths of the average carbon number of wax in crude, the effect of PA is the best. The molecular weight distribution of PA pour point depressant has little influence on the effect of pour point depression, and the average molecular weight of PA in the range of （ 1.5- 2.2）× 10^4 shows the best effect. The introduction of polar groups into the molecule of PA can improve its performance. However, a too high content of polar groups in PA would cause deterioration, and even lead to loss of PA＇s performance for pour point depression.

Synthesis and Characterization of Poly（Lactide）s Using Novel Solid Cloisite Modified Tin Catalyst

A novel cloisite modified solid catalyst was prepared in a single step from commercially available starting materials for the first time. The ring opening polymerization of L-lactide and D-lactide using this cloisite modified solid catalyst resulted in homopolymers of 75,000 and PDI = 1.6 and the maximum molecular weight （Mw） i.e. 180,000 with PDI = 1.9 were obtained. The catalytic activity ofcloisite modified solid catalyst was compared with the conventional stannous octoate catalyst and found superior to stannous octoate in all respect such as conversion, molecular weight and molecular weight distribution etc.. Moreover, the maximum molecular weight i.e. 180,000 was obtained at 220 ℃, whereas, transesterification reaction predominate in presence of stannous octoate The linear structure was confirmed by quantitative ^13C NMR Spectroscopy. Blend films were obtained by casting mixed solutions of poly （D-lactide） and poly （L-lactide） at various compositions, and stereocomplex was formed at 50/50 composition with molecular weight of 75,000.

Effects of different enzymatic hydrolysis methods on the bioactivity of peptidoglycan in Litopenaeus vannamei

The effects of different hydrolysis methods on peptidoglycan （PG） were assessed in terms of their impact on the innate immunity and disease resistance of Pacific white shrimp, Litopenaeus vannamei. PG derived from Bifidobacteriurn thermophilum was prepared in the laboratory and processed with lysozyme and protease under varying conditions to produce several different PG preparations. A standard shrimp feed was mixed with 0.05% PG preparations to produce a number of experimental diets for shrimp. The composition, concentration, and molecular weight ranges of the soluble PG were analyzed. Serum phenoloxidase and acid phosphatase activity in the shrimp were determined on Days 6-31 of the experiment. The protective activity of the PG preparations was evaluated by exposing shrimp to white spot syndrome virus （WSSV）. Data on the composition of the PG preparations indicated that preparations hydrolyzed with lysozyme for 72 h had more low-molecular-weight PG than those treated for 24 h, and hydrolysis by protease enhanced efficiency of hydrolysis compared to lysozyme. SDS-PAGE showed changes in the molecular weight of the soluble PG produced by the different hydrolysis methods. Measurements of serum phenoloxidase and acid phosphatase activity levels in the shrimp indicated that the PG preparations processed with enzymes were superior to the preparation which had not undergone hydrolysis in enhancing the activity of the two serum enzymes. In addition, the preparation containing more low-molecular-weight PG enhanced the resistance of the shrimp to WSSV, whereas no increased resistance was observed for preparations containing less low-molecular-weight PG. These findings suggest that the immunity-enhancing activity of PG is related to its molecular weight and that increasing the quantity of low-molecular-weight PG can fortify the effect of immunity enhancement.

LOW MOLECULAR WEIGHT HEPARIN ENHANCES THE EFFECT OF aFGF IN ACCELERATING NEOVASCULA-RIZATION

Objective To explore the potential of low molecular weight heparin (LMWH) in combination cooperated with aFGF in accelerating neovascularization in vivo. Methods Ischemic model was set up in the right hindlimbs of 28 New Zealand white rabbits. Four groups of animals treated with saline, LMWH, aFGF and aFGF plus LMWH were allocated equally in group Ⅰ, group Ⅱ, group Ⅲ and group Ⅳ respectively. Vascular neovascularization and smooth muscular thickness of the ischemic hindlimb vessels of each animal in different groups were compared with each other on the 28th day postoperatively by angiography with DSA and the standard immunoperoxidase technique. Results No significant neovascularization was seen when aFGF adiministered in low dosage by venous infusion. But when the same dosage of aFGF plus LMWH were administered by venous infusion, a significant neovascularization was observed. Conclusion LMWH can potentiate aFGF in accelerating neovascularization.