含取代氨端基的聚酯类超分散剂的研制及应用

对含取代氨端基的聚酯类超分散剂的合成方法进行了研究,并为获得适当长度的聚酯链选择了最佳合成条件.同时扼要论述了这类超分散剂的结构特性,以及对于有机颜料粒子表面的吸附作用、分散体系的稳定作用以及对涂料、油漆、油墨生产的重要意义.

一种新型发用氨端基硅油的合成与表征

以八甲基环四硅氧烷(D4)为反应单体,以1,3-双(3-氨丙基)-1,1,3,3-四甲基二硅氧烷为封端剂,N-β-氨乙基-γ-氨丙基甲基二甲氧基硅烷(DL-602)为氨基硅烷偶联剂,氢氧化钾(KOH)为催化剂,二甲基亚砜(DMSO)为促进剂,采用本体聚合法合成了氨丙基封端的新型氨端基硅油,研究了反应温度、反应时间及KOH、DMSO用量对反应体系粘度及转化率的影响。结果表明,最适宜的工艺条件是:反应温度100℃,反应时间10 h,KOH、DMSO用量分别为D4单体用量的0.03%,0.75%。

锦纶6聚合物氨基含量影响因素的分析

根据锦纶６聚合反应机理，分析了聚合反应温度、醋酸含量和水对聚合物中 氨端基含量的影响趋势，提出了生产控制的要点。

聚乙基亚胺-聚羟基酸酯超分散剂的合成

对含取代氨端基的聚酯类超分散剂的合成方法进行了研究,并为获得适当长度的聚酯链选择了最佳合成条件;同时扼要论述了这类超分散剂的结构特性,以及对于有机颜料粒子表面的吸附作用、分散体系的稳定作用以及对涂料、油墨生产的重要意义。

Micro-heterogeneity of Storage Glutelin in Rice Seed

The storage glutelin in rice ( Oryza sativa L.) seeds could be separated at least into more than 13 acidic and 19 basic polypeptides by two dimensional electrophoresis. Rice glutelin might be mainly controlled by about six major genes according to the expression of glutelin polypeptides. The acidic polypeptide of glutelin could be clearly separated into two groups by peptide mapping and N-terminal amino acid sequence analysis. These two groups were just in accord with the GluA and GluB subfamilies exactly.

ATPU/环氧树脂固化物热稳定性的研究

采用热重法(TG-DTG)研究了2种含有柔性链和刚性结构单元的端胺基聚氨酯(ATPU-2和ATPU-1.5)对环氧树脂E-44固化物热稳定性特点和热分解动力学的影响。结果表明,固化剂ATPU-2与E-44固化物的热分解温度高于ATPU-1.5/E-44体系的固化物,ATPU-2/E-44固化物的分解残余量也高于ATPU-1.5/E-44体系。表明ATPU-2/E-44体系具有更好的热稳定性。固化反应动力学研究表明ATPU-2/E-44固化物的分解反应活化能高于ATPU-1.5/E-44体系。

Val 70, Phe 72 and the last seven amino acid residues of C-terminal are essential to the function of norepinephrine transporter

The norepinephrine transporter(NET) is a member of the Na+/Cl- dependent neurotransmitter transporter family and constitutes the target of several clinically important antidepressants. To delineate the critical amino acid residues and the function of C-terminal in regulating transport activity of NET, here we constructed two site mutants (V70F, F72V; V70I, F72V) and one C-terminal truncated mutant (△611-617). The wild type and mutants of NET were expressed in Xenopus oocytes by injection of their cRNA. We found that all of these mutants lost their transport activity. These results indicate that the amino acid residues of V70 and F72 3 and the last seven amino acids of C-terminal are essential to the transport activity of NET.

Isolation and functional characterization of the C-terminus of rice phos-phatidylinositol 4-kinase in vitro

A partial rice (Oryza sativa L.) cDNA clone. OsPMK1c, was isolated through screening of a cDNA library constructed from tillering materials. OsPI4Klc encoded a peptide of 608 amino acids with a calculated molecular mass of 68.4 kDa. The OsPI4Klc peptide shared high homology and possessed the highly conserved domains present in most isolated cloned PI4-kinases, i.e. a lipid kinase unique (LKU) domain and a catalytic (CAT) domain. A region with similarity to pleckstrin homology (PH) domain was present in OsPI4K1c as well. Further comparison with genomic sequences in databases revealed that OsPI4K1c is located at the 3'-end of a putative rice PI 4-kinase coding gene OsPI4K1, and its coding region corresponded to the C-terminal half of OsPI4Kl protein. Twelve exons (49-562 bp in size) and 11 introns (77-974 bp in size) were identified in OsPI4K1c. The recombinant protein expressed in Escherichia coli phosphorylates phosphatidylinositol at the D4 position of the inositol ring. OsPI4K1 transcript levels were detected in a low but constitutive manner in shoot, stem, leaf, spike and root tissues and did not change upon treatment with different hormones, calcium and jasmonic acid (JA). However, treatment with salicylic acid (SA) elevated the mRNA level of the OsPI4K1 gene, which suggested the involvement of OsPI4K1 in wounding responses.

Molecular Cloning and Characteristics Analysis of ghrelin Gene in Asian Swamp Eel(Monopterus albus)

Ghrelin is an important signaling molecule linking reproductive and energy metabolism. In this study, ghrelin gene of Monopterus albus was cloned. Its structure and function were analysized preliminarily. By Rapid Amplification of cDNA Ends(RACE) technique, full-length cDNA and DNA sequences of ghrelin gene were obtained. The full-length ghrelin cDNA(GenBank accession no. JX122807) was 552 bp long, containing a 115 bp 5'-untranslated region, a 324 bp open reading frame and a 113 bp 3'-untranslated region. The full-length ghrelin DNA was 1 323 bp, consisting of three introns and four exons. The exon/intron junction sequences conformed to the GT/AG rule. Three introns were 594, 84 and 93 bp in length, respectively; four exons were229, 78, 112 and 133 bp in length, respectively. The results of amino acid sequence analysis showed that the deduced propreghrelin sequence of M. albus contained a signal peptide(SP) consisting of 22 amino acid residues, a mature peptide(MP)consisting of 19 amino acid residues and a C-terminal amino acid residue. Among them, the third amino acid of MP was serine(Ser^3) as the site for N-acylation and N-deacetylation reactions; the C-terminal amino acid residue sequence might contain a peptide hormone obestatin, which is a physiological antagonist of mature Ghrelin peptide. The homology and phylogenic relationships analyses of amino acid sequences suggested that propreghrelin of M. albus had high similarity to those of several Perciformes fishes; the propreghrelins of M. albus, Perciformes and Heterosomata fishes were clustered into a subgroup. The high conservatism of the gene structure and the amino acid sequences indicated that Ghrelin exerts important physiological functions and plays similar physiological mechanisms in vertebrates.

Activation of Prophenol Oxidase PHOX-S with Limited Proteolysis in Drosophila Melanogaster

Prophenol oxidase isoform A1 was isolated from Drosophila melanogaster （The sequence has been deposited in GenBank data base under accession number AB557586） PHOX-S strain, and its characteristics and activation mechanism were determined. The NH2-terminal region of PHOX-S A1 was determined to be comprised of 15 amino acids with the following sequence MTNMKMKMKAMMR. Comparison of an alignment in the known prophenol oxidase protein sequences from Drosophila melanogaster strains showed high homology in the copper-binding sequences at the Cu （A） site of the active center. Limited proteolysis takes place between Arg-50 and Val-51. Therefore, it is concluded that prophenol oxidase PHOX-S protein was evolved at the upstream, but no evolved at the central site in Drosophila melanogaster.

Glycyrrhizic acid activates chicken macrophages and enhances their Salmonella-killing capacity in vitro

Objective： Salmonella enterica remains a major cause of food-borne disease in humans, and Salmonella Typhimurium （ST） contamination of poultry products is a worldwide problem. Since macrophages play an essential role in controlling Salmonella infection, the aim of this study was to evaluate the effect of glycyrrhizic acid （GA） on immune function of chicken HD11 macrophages. Methods： Chicken HD11 macrophages were treated with GA （0, 12.5 25, 50, 100, 200, 400, or 800 pg/ml） and lipopolysaccharide （LPS, 500 ng/ml） for 3, 6, 12, 24, or 48 h. Evaluated responses included phagocytosis, bacteria-killing, gene expression of cell surface molecules （cluster of differentiation 40 （CD40）, CD80, CD83, and CD197） and antimicrobial effectors （inducible nitric oxide synthase （iNOS）, NADPH oxidase-1 （NOX-1）, interferon-γ （IFN-γ）, LPS-induced tumor necrosis factor （TNF）-α factor （LITAF）, interleukin-6 （IL-6） and IL-IO）, and production of nitric oxide （NO） and hydrogen peroxide （H202）. Results： GA increased the internalization of both fiuorescein isothiocyanate （FITC）-dextran and ST by HD11 cells and markedly decreased the intracellular survival of ST. We found that the messenger RNA （mRNA） expression of cell surface molecules （CD40, CDSO, CD83, and CD197） and cytokines （IFN-γ, IL-6, and IL-10） of HD11 cells was up-regulated following GA exposure. The expression of iNOS and NOX-1 was induced by GA and thereby the productions of NO and H202 in HD11 cells were enhanced. Notably, it was verified that nuclear factor-κB （NF-κB） and c-Jun N-terminal kinase （JNK） pathways were responsible for GA-induced synthesis of NO and IFN-γ gene expression. Conclusions： Taken together, these results suggested that GA exhibits a potent immune regulatory effect to activate chicken macrophages and enhances Salmonella-killing capacity.

Relationship Between the Central Hypotensive Effect of Acupuncture or Melatonin and the Changes of Medullary Amino Acid Neurotransmitter

To investigate whether changes of amino acid neurotransmitter releases in the rostral ventrolateral medulla （rVLM） were related to acupuncture and to the antihypertensive effect of melatonin （Mel） microinjected into the anterior hypothalamic area （AHA） of rats with stress-induced hypertension （SIH）, as well as to compare and analyze the relationship between the both antihypertensive mechanisms of acupuncture and of Mel in the AHA. Methods： Animal model of SIHR was made by electric foot shocks combined with noises. Electroacupuncture （EA） was used and “Zusanli” acupoint of both side was selected. The technique of drug microinjection into the brain was used to observe the change of blood pressure （BP）, and synchronously, brain microdialysis was performed for collecting dialysate samples, and then the concentration of amino acid neurotransmitters in the dialysate samples was determined by high performance liquid chromatography combined with fluorescent detection （HPLC-FD）. Results： After the animal received stress treatment, the BP elevated, synchronously, the release of glutamate （Glu） in the rVLM increased, and when EA was performed, the elevated BP of the rats with SIH decreased, simultaneously, the release of Glu in the rVLM decreased also. After Mel was microinjected of into the AHA of the SIHR, the elevated BP attenuated, meanwhile, the release of Glu decreased, and those of γ-aminobutyric acid （GABA） and taurine （Tau） increased in the rVLM.Administration of bicuculline, an antagonist of GABAA receptor, into the rVLMprior to microinjection of Mel imo the AHA could partially block the depressor effect of Mel in the AHA. Conclusion： The decrease in the release of Glu in the rVLM contributes to the antihypertensive effect of both acupuncture and Mel in the AHA in the rats with SIH, and the increase in the release of GABA and Tau in the rVLM is also im0ortam to Mel in the AHA.

Mechanism of the Reversal Effect of Acupuncture on the Fall of Blood Pressure Induced by Angiotensin-(1-7)in the Caudal Ventrolateral Medulla of Rats

Objective：To investigate the mechanism of the reversal effect of acupuncture on the fall of blood pressure induced by angiotensin （1-7）[Ang-（1 7）] in the caudal ventrolateral medulla （CVLM） of rats. Methods： Ang-（1-7） and its selective receptor antagonist （DAla7）, Ang（1-7） and Ang（779） were microinjected into the CVLM respectively to induce the change of blood pressure, during which, the concentrations of amino acid neurotransmitters were detected by means of microdialysis and high performance liquid chromatography （HPLC）combined with fluorescent detector, on the other hand, the effects of electro-acupuncture （EA） on the level of blood pressure and the concentrations of amino acid neurotransmitters were also observed. Results： Unilateral microinjection of Ang（1 7） into the CVLM could decrease the blood pressure （BP）, which was accompanied by an increase in the release of Glu and a decrease in the release of Tau in the same site; Whereas microinjection of Ang-779 into the CVLM could elevate BP, which was accompanied by a decrease in the release of Glu and an increase in the release of Tau; EA at acupoint Zusanli （ST 36） for 20 min could inhibit the fall of blood pressure induced by microinjection of Ang-（1-7） into the CVLM and the elevation of blood pressure induced by microinjection of Ang-779 into the CVLM, and in the meantime, it could inhibit the changes of the release of Glu and Tau induced by microinjection of Ang-（1-7） and Ang-779 into the CVLM. Conclusion： The reversal effect of EA on the fall or elevation of blood pressure induced by microinjection of Ang-（1-7） or Ang-779 into the CVLM might be related to the changes of Glu and Tau release.