γ-聚谷氨酸-天冬氨酸聚合物的合成表征及性质

利用微生物发酵制备γ-聚谷氨酸,降解得小分子γ-聚谷氨酸,将天冬氨酸接入小分子γ-聚谷氨酸,得γ-聚谷氨酸-天冬氨酸聚合物(GAP460)。核磁共振、红外光谱、差热扫描量热分析(DSC)等方法表征GAP460;常规方法检测GAP460的结构稳定性,免疫原性,急性毒性及血液参数值等。结果表明,成功制备了γ-聚谷氨酸-天冬氨酸聚合物,其在中性、常温及4℃条件下结构稳定;GAP460免疫小鼠,初次免疫后八周测得抗体滴度为1∶20,显示GAP460是低免疫原性;急性毒性、血液参数等生物相容性指标显示该材料无毒。

聚L－谷氨酸－炔诺酮肟酯复合体的制备

合成了聚Ｌ－谷氨酸－炔诺酮肟酯的复合体，炔诺酮的接入量为２２．８％．体外释放时间约１５大。

杨梅状碳包覆四氧化三铁复合材料的制备及锂离子电池负极性能

Fe_(3)O_(4)被认为是一种储锂性能优异的锂离子电池负极材料,但目前仍存在导电性差和充放电过程体积膨胀问题。文中以L-精氨酸、对苯二甲醛和九水硝酸铁为原料,通过溶剂热反应得到铁离子掺杂L-精氨酸聚合物(W-Fe_(3)O_(4)@NC precursors),随后高温热解制备了杨梅状碳包覆四氧化三铁(W-Fe_(3)O_(4)@NC)复合负极材料。对W-Fe_(3)O_(4)@NC的形貌、表面化学结构、孔隙率和在锂离子电池负极中的电化学性能进行了表征。结果表明,得益于独特的杨梅状形貌、有益的氮掺杂、高度分散的Fe_(3)O_(4)纳米微粒和均匀的碳包覆,W-Fe_(3)O_(4)@NC在1 A/g电流密度下循环800圈后比容量高达815.1 mAh/g,在5 A/g的大电流密度下,比容量仍保持在232 mAh/g,循环稳定性和倍率性能显著优于纯碳材料(NC)和市售Fe_(3)O_(4)纳米粒子。

具有螯合活性的天冬氨酸聚合物的制备及应用

本发明涉及一种具有螯合活性的新型化合物，与碱土金属有关，可作为工业水处理除垢剂中的附加成分。本发明还涉及该化合物的制备方法。

8R-MUC1核心肽融合蛋白的原核表达及纯化

目的 :构建蛋白质转导结构域 8个精氨酸聚合体 (8R)与 MUC1核心肽融合蛋白的原核表达载体 ,并表达、纯化出具有生物学活性的 8R- MUC1核心肽融合蛋白。方法 :以 PCR法从 HSP6 5 - MUC1- p ET2 8a质粒中钓取 MUC1核心肽 2个重复序列片段 ,连入 p MD18- T载体 ,然后用酶切、连接的方法从 T载体上获得 MU C1核心肽 6重复序列片段 (MU CPT) ,将其克隆入含 8R的 p ET2 6 b+ 原核表达载体中构建 8R与 MU CPT融合蛋白(8R- MU CPT)表达载体。用 IPTG诱导转化 8R- MU CPT表达载体的大肠杆菌 BL2 1(DE3) ,并以镍螯合层析法纯化 8R- MU CPT融合蛋白。结果 :构建了 8R与 MU C1核心肽 6个重复序列片段的融合蛋白原核表达载体8R- MUCPT- p ET2 6 b+ ,并在 BL2 1(DE3)中表达了 8R- MU CPT融合蛋白 ,经镍螯合层析获得纯度为 95 .5 %的8R- MUC1核心肽融合蛋白。结论 :构建了 8R- MU C1核心肽融合蛋白原核表达载体并成功表达与纯化出具有生物学活性的融合蛋白。

Preparation and electrostriction of BaTiO_3/polyurethane nanocomposite elastomers

BaTiO3/polyurethane （BaTiO3/PU） nanocomposite elastomers were prepared from barium titanate nanoparticles, polyester polyol, 2, 4-toluene diisocyanate, 1,4-butanediol and 1, 1, 1-trimethanol propane by the one-step method. The density, hardness and dielectric constant of BaTiO3/PU nanocomposite elastomers increased with the increase of the content of BaTiO3 nanoparticles in nanocomposites. The electrostrictive properties of BaTiO3/PU nanocomposite elastomers were investigated by the digital speckle correlation method （DSCM）. It was found that through the on-and-off of the electric field, the electrostrictive strains of BaTiO3/PU nanocomposite elastomers revealed corresponding shrinkage and recovery. The electrostrictive coefficient of BaTiO3/PU nanocomposite elastomers was greater than that of the corresponding polyurethane elastomers, and the electrostrictive coefficient of composites decreased with the increase of the content of barium titanate nanoparticles.

PEG-PLA-PGL/RGD涂层支架对冠脉支架置入术后再狭窄的影响

目的探PEG-PLA-PGL/RGD涂层支架置入后对猪冠状动脉内皮化及内膜增生的影响。方法以PEGPLA-PLG聚脂肪酸为载体,通过载体接枝精氨酸-甘-天冬氨酸三肽聚合物(RGD),制成生物可降解高分子载RGD冠脉支架。实验分为裸支架组、紫杉醇涂层支架组、PEG-PLA-PGL/RGD涂层支架组,每组实验小型猪6只,将相应支架分别置入到每组猪的冠状动脉损伤段,分别4周及12周后处死,取出支架段血管行病理学观察及计算机图像分析测定管腔面积(lumen area,LA)、内弹力膜面积(internal elastic membrane area,IEMA),并根据LA及IEMA计算出新生内膜面积(neointima area,NA)及面积狭窄百分数(percentage of area stenosis,%AS)。结果 PEG-PLA-PGL/RGD涂层支架组内膜增生面积较裸支架组明显减低(P<0.05),PEG-PLA-PGL/RGD涂层支架组内膜增生面积与紫杉醇涂层支组无明显差别(P>0.05)。结论 PEG-PLA-PGL/RGD涂层支架较裸支架,可明显加速内皮修复,明显降低再狭窄的发生,是一极具前景研究方向。

Effect of Chitosan-Cysteine Conjugate on Enzymatic Degradation and Hypoglycemic effect of Insulin

Aim To evaluate the inhibitory effect of chitosan-cysteine conjugate onenzymatic degradation and hypogly-cemic enhancement effect of insulin. Methods Chitosan-cysteineconjugate was synthesized. The protective effect of the conjugate against degradation of insulin byα-chymotrypsin and trypsin was evaluated in vitro. Insulin enteric- microspheres were prepared byusing O_1 /Q_2 emulsion solvent evaporation method. The hypoglycemic enhancement effect of theconjugate was studied by oral administration of insulin solution or enteric-microspheres to rats.Results The thiol group content of the synthesized conjugate was about 200 μmol·g^(-1) polymer,which showed a strong protective effect on insulin from enzymatic degradation in vitro. Almost allthe insulin incubated in a-chymotrypsin solution or trypsin solution without chitosan-cysteineconjugate was degraded entirely within 1 h and 5 h respectively, whereas above 75% of insulinremained in the same content of the enzymatic solution containing 4 mg·mL^(-1) conjugate. The drugloading of insulin enteric-microspheres was about 7% . In vivo experiment, chitosan-cysteineconjugate (85 μg·kg^(-1)) prolonged the hypoglycemic time of insulin solution orenteric-microspheres when administered simultaneously with the absorption enhancer SNAC. ConclusionChitosan-cysteine conjugate has a marked inhibitory effect on the enzymatic degradation of insulinin vitro, and it displays a significant hypoglycemic enhancement effect on insulin oral formulationin vivo.

Preparation and characterization of composite microspheres of nano zinc ferrite/poly(D,L-lactide-co-alanine)

Magnetic nano zinc ferrite fliuds were synthesized using an improved liquid phase chemical method, which would be used to replace tradditional iron oxides magnetic material. A novel copolymer （PLAA） with D, L-lactide （D, L-LA） and alanine was synthesized using stannous octoate as initiator. Magnetic polymer microspheres were fabricated with nano zinc ferrite fluid coated with alanine modified poly lactide. These as-prepared zinc ferrite fluids, modified poly lactide and magnetic composites, were characterized with X-ray diffraction diffractometer, FT-IR spectrometer, nuclear magnetic resonance spectrometer, scanning electron microscope, transmission electron microscope, vibrating sample magnetometer, and thermogravimetric analyzer. The results demonstrate that the as-prepared zinc ferrite is spinel type of ZnFe2O4 nano crystals with particle size of 20-45 nm and magnetization of 32×10^-3 A.m2. Alanine is copolymerized with lactide, and the prepared composite magnetic microsphere is coated with the modified polylactide, with mass fraction of 45.5% of PLA, particle size ranging from 80-300 nm, and magnetization of 10.6×10^-3 A·m^2, which suggests ZnFe2O4 enjoys a stable magnetization after being coated by polymer.

Preparation and Characterization of Two-component Waterborne Polyurethane Comprised of Water-soluble Acrylic Resin and HDI Biuret

A two-component waterborne polyurethane(2K-WPU) was prepared by mixing water-soluble acrylic resin and hexamethylene diisocyanate biuret, and then diluted for phase inversion with water. Compared with water-soluble acrylic resin, the phase inversion of 2K-WPU occurs at lower water content. It is indicated by TEM that 2K-WPU parti-cles show a core-shell structure, in which HDI biuret is encapsulated by hydrophilic acrylic resin. 2K-WPU emulsion with HDI biuret has larger particle size and narrower distribution index, while for 2K-WPU emulsion with HDI iso-cyanurate, the latex not only has large particle size, but also has two-peak distribution. FTIR shows that the reaction be-tween HDI biuret and acrylic resin can complete in 12h. In addition, studies on effect of composition of acrylic resin on performance of 2K-WPU show that narrowing the polar difference between water-soluble acrylic resin and HDI biuret and improving the miscibility of two components are the key to prepare the transparent and high gloss films with high crosslinking density.

The Paramagnetic 2D Chiral-porous Polymer of L-Phenylalanine and Manganese

Mn(L-Phe)2稨2O]n (Phe=phenylalanine) with a single stranded coordination poly- mer has been synthesized by self-assembly of manganese salt and phenylalanine and characterized by X-ray single-crystal diffraction method. The complex crystallizes in the orthorhombic, space group P212121 with a = 6.0911(1), b = 10.3642(1), c = 30.4321(7) ? V = 1921.16(6) ?, Z = 4, Dc = 1.387 g/cm3, C18H22N2O5Mn, Mr = 401.32, F(000) = 836 and m(MoKa) = 0.717 mm-1. The final R = 0.0614 and wR = 0.1412 for 2291 observed reflections with I > 2s(I). The magnetic behavior study shows that there exist super-exchange antiferromagnetic interactions between the magnetic centers through the effective exchange pathway of the carboxylate group.

Active changes of lignification-related enzymes in pepper response to Glomus intraradices and/or Phytophthora capsici

The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus of Glomus intraradices and/or infection with pathogenic strain of Phytophthora capsici, and the biological control effect of G. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated with G. intraradices (Gi), (2) plants pre-inoculated with G. intraradices and then infected with P. capsici (Gi+Pc), (3) plants infected with P. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal coloni-zation rate was reduced by about 10% in pathogen challenged plants. Root mortality caused by infection of P. capsici was com-pletely eliminated by pre-inoculation with antagonistic G. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only 21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9% in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major POD isozymes (45 000, 53 000 and 114 000) were present in Pc-treated roots, while two major bands (53 000 and 114 000) and one minor band (45 000) were present in spectra of Gi+Pc-treated roots, the 45 000 POD isozyme was significantly suppressed by G. intraradices, suggesting that the 45 000 POD isozyme was induced by the pathogen infection but not induced by the antagonistic G. intraradices. A 60 000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the inoculation of antagonistic G. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper plants infected by P. capsici. The results suggested that G. intraradices is a potentially effective protection agent against P. capsici.

拉米夫定联合阿德福韦酯治疗慢性乙型病毒性肝炎发生YMDD变异的疗效观察

目的:探讨拉米夫定联合阿德福韦酯治疗慢性乙型病毒性肝炎(chronic hepatitis B,CHB)发生DNA聚合酶酪氨酸-蛋氨酸-天门冬氨酸-天门冬氨酸(tyrosine-methionine-aspartate-aspartate,YMDD)变异的疗效。方法:选取2012年1月—2016年1月宜都市第一人民医院收治的经拉米夫定治疗后出现YMDD变异的CHB患者104例作为研究对象,以随机数字表法分为观察组和对照组,每组52例。对照组患者给予阿德福韦酯治疗,观察组患者在对照组的基础上加用拉米夫定治疗。观察两组患者肝功能指标变化情况,比较两组患者HBV-DNA转阴、乙型肝炎病毒e抗原(HBeAg)转阴及YMDD变异情况。结果:治疗后,两组患者血清丙氨酸氨基转移酶、天门冬氨酸氨基转移酶和总胆红素水平均明显低于治疗前,且观察组患者明显低于对照组,差异均有统计学意义(P<0.05);观察组患者HBV-DNA及HBeAg转阴率均明显高于对照组,YMDD变异率明显低于对照组,差异均有统计学意义(P<0.05);两组患者均无明显不良反应。结论:拉米夫定联合阿德福韦酯治疗CHB发生YMDD变异的疗效显著,安全性高。

Suppression of Human Liver Cancer Cell Migration and Invasion via the GABA_A Receptor

Objective To investigate the roles of the y-aminobutyric acid （GABA） in the metastasis of hepatocellular carcinoma （HCC） and to explore the potential of a novel therapeutic approach for the treatment of HCC. Methods The expression levels of GABA receptor subunit genes in various HCC cell lines and patients＇ tissues were detected by quantitative real-time polymerase chain reaction and Western blot analysis. Transwell cell migration and invasion assays were carried out for functional analysis. The effects of GABA on liver cancer cell cytoskeletal were determined by immunofluorescence staining. And the effects of GABA on HCC metastasis in nude mice were evaluated using an in vivo orthotopic model of liver cancer. Results The mRNA level of GABA receptor subunits varied between the primary hepatocellular carcinoma tissue and the adjacent non-tumor liver tissue. GABA inhibited human liver cancer cell migration and invasion via the ionotropic GABAA receptor as a result of the induction of liver cancer cell cytoskeletal reorganization. Pretreatment with GABA also significantly reduced intrahepatic liver metastasis and primary tumor formation in vivo. Conclusions These findings introduce a potential and novel therapeutic approach for the treatment of cancer patients based on the modulation of the GABAergic system.

Cloning and Analysis of Calmodulin Gene from Porphyra yezoensis Ueda (Bangiales, Rhodophyta)

In order to understand the mechanisms of signal transduction and anti-desiccation mechanisms of Porphyra yezoensis, cDNA and its genomic sequence of Calmodulin gene (CaM) was cloned by the technique of polymerase chain reaction (PCR) based on the analysis of P. yezoensis ESTs from dbEST database. The result shows that the full-length cDNA of CaM consists of 603 bps including an ORF encoding for 151 amino acids and a terminate codon UGA, while the length of genomic sequence is 1231 bps including 2 exons and 1 intron. The average GC content of the coding region is 58.77%, while the GC content of the third position of this gene is as high as 82.23%. Four Ca2+ binding sites (EF-hand) are found in this gene. The predicted molecular mass of the deduced peptide is 16688.72 Da and the pI is 4.222. By aligning with known CaM genes, the similarity of CaM gene sequence with homologous genes in Chlamydomonas incerta and Chlamydomonas reinhardtii is 72.7% and 72.2% respectively, and the similarity of the deduced amino acid sequence of CaM gene with homologous genes in C. incerta and C. reinhardtii are both 71.5%. This is the first report on CaM from a species of Rhodophyta.

D-Tyr-tRNA^(Tyr) Deacylase,a New Role in Alzheimer's-associated Disease in SAMP8 Mice

Objective To assess the expression level of D-Tyr-tRNATyr deacylase(DTD) in SAMP8 mice and speculate the function of DTD in disorders associated with Alzheimer's disease(AD).Methods Altogether 12 SAMP8 mice and 12 SAMR1 mice were used in this study.Semi-quantita-tive reverse transcription-polymerase chain reaction(RT-PCR) and Western blot were performed to detect the mRNA and protein levels of DTD in the mice.Purified DTD protein was injected into lateral ventricle to investigate the function of DTD in SAMP mice.The behavior of the mice was tested by using a Step-through Test System.Results Both mRNA and protein levels of DTD were found to be significantly lower in SAMP8 mice compared with those in SAMR1 mice(P<0.05).In vivo injection of DTD protein did not lead to an obvious change in behavior of SAM mice.Conclusions DTD might function in the process of AD-associated pathology and could possibly participate in physiology process in a long-term manner to orchestrate with other regulators in order to maintain the balance of organism.

Synthesis of PGMA Microspheres with Amino Groups for High-capacity Adsorption of Cr(VI) by Cerium Initiated Graft Polymerization

Abstract A novel polyglycidylmethacrylate （PGMA） microspheres with high adsorption capacity of Cr（VI） was prepared by cerium（IV） initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microspheres with hydroxyl groups. The micron-sized PGMA microspheres were prepared by a dispersion polym erization method and subsequently modified by ring-opening reaction to introduce functional hydroxyl groups. The polymer microspheres were characterized by scanning electron microscopy （SEM） and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the polymer microspheres had an average diameter of 5 m with uniform size distribution. The free amino group content was determined to be 5.13 mmol·g^-1 for g;PGMA-NH2 microspheres by potentiometric and conductometric titration methods. The Cr（VI） adsorption results indicated that the graft polymerization of tentacle-type polymer chains on the polymer microspheres could produce adsorbents with high adsorption capacity （500 mg-g-l）. The polymer microspheres with grafted tentacle polymer chains have potenial application in large-scale removal of Cr（VI） in aqueous solution.

In Vitro Antimicrobial Activity Study of Some New Arginine-based Biodegradable Poly （Ester Urethane）s and Poly （Ester Urea）s

Bactericidal activity of some arginine based biodegradable polymers-PEURs （poly （ester urethane）s） and PEUs （poly （ester urea）s） with low cytotoxicity was studied in in vitro experiments. Various bacterial strains both Gram-positive and Gram-negative were used to explore the bactericidal activity of the cationic polymers. As the test objects, the following microorganisms were used： Bacillus subtilis, Staphylococcus aureus, Mycobacterium album, Pseudomonas fluorescens, Escherichia coli, Actinomyces griseus and Aspergillus niger. The obtained results showed that the new cationic polymers suppressed the growth of the studied microorganisms and the bactericidal activity of the tested cationic polymers strongly depending on their chemical structure.

New progress in the study of poly(L-glutamic acid)-paclitaxel conjugates for cancer treatment

The preparation of polymer-anticancer drug conjugates is an effective way to improve the efficacy and decrease the toxicity of anticancer drugs. Polymer-drug conjugates, which were made by combining a suitable polymeric carrier, a biodegradable linker and a bioactive anticancer agent, could form the basis of a new generation of anticancer agents. Poly （L-glutamic acid）- paclitaxel conjugate is a polymer-drug conjugate that links anticancer agent paclitaxel （PTX） to poly （L-glutamic acid） （PG）. PG-PTX conjugate can improve the anticancer activity, enhance the safety and efficacy, and improve the pharmacokinetic properties of PTX. Therefore, the application of PG-PTX facilitates the clinical therapy of a variety of human cancers.

长春花生物碱载药纳米粒的制备及评价

目的:制备基于L-色氨酸单体的纳米聚合物,以长春花生物碱为模型药物制备载药纳米粒,评价其药物载体性能。方法:考察并采用均匀设计法优化N-丙烯酰基-L-色氨酸纳米聚合物的制备方法,并评价其对L-929细胞生长增殖的影响;分别制备长春碱、长春新碱、长春瑞滨载药纳米粒,考察其在磷酸缓冲液(PBS,p H=7.4)的释药行为。结果:沉淀聚合法制备的L-色氨酸纳米聚合物(169.3nm,PDI=0.358)对L-929细胞生长增殖无影响;对长春碱、长春新碱、长春瑞滨载药性能良好,载药量分别为8.55%、7.04%、6.72%;在PBS中,3种药物均以扩散方式从载体中缓慢、完全释放,无明显突释。结论:L-色氨酸纳米聚合物生物相容性良好,可能通过π-π作用包载长春花生物碱,在生理环境下缓释药物,是潜在的长春花生物碱药物载体。