CuPc(COOH)8-SA/CuTAPc-CS双极膜的制备及表征

分别用八羧基铜酞菁[CuPc(COOH)₈]和四氨基铜酞菁(CuTAPc)改性海藻酸钠(SA)阳膜层和壳聚糖(CS)阴膜层, 制备了CuPc(COOH)₈-SA/CuTAPc-CS双极膜. 实验结果表明, 经八羧基铜酞菁和四氨基铜酞菁改性后, 促进了双极膜中间层水的解离, 增大了阳离子交换膜层和阴离子交换膜层的离子交换容量及H⁺和OH^-的透过率. 与Fe³⁺改性的Fe-SA/mCS双极膜相比, CuPc(COOH)₈-SA/CuTAPc-CS双极膜的阻抗、电阻压降(即IR降)和溶胀度降低. 当电流密度高达120 mA/cm²时, CuPc(COOH)₈-SA/CuTAPc-CS双极膜的IR降仅为0.9 V.     

Photochemical formation of silver-gold (Ag?Au) composite colloids in solutions containing sodium alginate

Photochemical formation of colloidal silver, colloidal gold and silver-gold (Ag-Au) composite colloids under mild conditions has been studied. Irradiation of either aqueous AgCIO₄ or HAuCI₄ solution in the presence of sodium alginate (SA) with 253.7 nm light yielded colloidal silver or gold, whose particle diamter was 10-30 nm or 40-60 nm, respectively. The Ag-Au composite colloids consisting of mixtures of silver and gold domains (particle diameter 30-150 nm) have been prepared and their extinction spectra have been examined on the basis of a conventional Mie theory in combination with an effective medium theory to estimate the optical constants of these colloids. It has been shown that the extinction spectra of the Ag-Au composite colloids are completely different from those of Ag-Au alloy colloids, in that the former have two extinction maxima close to the colloidal extinction bands of pure silver and gold, in contrast to a single extinction maximum of the latter. The importance of natural, high-molecular carboxylic acids such as alginic acid in the photochemical formation of metal colloids and thin films has been stressed.     

Fiber fractions from processing of barley in production and conservation of a biologic control agent

Carriers are frequently used to overcome problems associated with microbial survival in soil after inoculation. Moreover, the use of carriers can prolong the shelf lives and lessen dusting of both biofungicides and biologic fertilizers. This study investigated the suitability of barley-based fiber fractions as growth media and immobilization matrices in the cultivation of a Streptomyces griseoviridis biologic control agent, as well as for the conservation of obtained biomass in dehydrated hydrogel capsules. The second main ingredient in all the examined carrier matrices was alginate. The aim was to find a hydrogel formulation suited for a production process in which all individual steps, including cultivation of the organism; downstream processing; and formulation, storage, and application of the product (i.e., biologic control agent), are carried out in the hydrogel matrix. Of the tested fractions, brewer’s spent grain was the best choice, when considering the price vs the nutrient contents as well as the storage time and ease of processing of the crude and the finished products. It seems that cereal fibers can be replenished with cereal fractions less rich in fiber but having a higher content of utilizable nutrients and, hence, better suited for the production of biomass. A high content of water-insoluble fiber favorably influenced the appearance as well as the applicability of the products.     

利用微生物反应器连续生产酵母单细胞蛋白

用海藻酸钙固定化面包酵母反应器由糖蜜生产单细胞蛋白,结果表明,在任何给定的稀释速率(D)下,流出液细胞浓度较高。在D=0.5h~(-1)时,固定化细胞反应器的生产能力为2gl~(-1)h~(-1),约为传统连续培养的2.5倍。     

海藻酸钠吸附铜离子的研究

研究了用海藻酸钠作为吸附剂去除水相中的Cu2 ,以及吸附过程中试验条件对吸附效果的影响·结果表明:吸附过程在10min左右就达到了平衡;在pH=6时吸附效果达到最佳;吸附温度以30℃左右为宜;海藻酸钠对Cu2 吸附的最大负载量为144～150mg/g·铜离子去除率的大小与水相中铜离子的初始质量浓度有关,对含铜量较高的水样(如铜离子质量浓度为800mg/L),海藻酸钠对溶液中Cu2 的去除率最高达81%,对含铜量较低的水样(如铜离子质量浓度为40mg/L),Cu2 的去除率达99 5%;因此采用海藻酸钠进行二次吸附,溶液中的Cu2 的残余质量浓度低于国家污水综合排放标准中铜离子的最高允许排放质量浓度·     

双歧杆菌微胶囊的研究

以海藻酸钠／壳聚糖为壁材，用表面交联法将活性双歧杆菌微胶囊化，并观察了微胶囊的耐胃酸性、常温贮存稳定性和低温贮存稳定性。     

扑草净降解酶的固定化及其对受污染土壤的生物强化研究

提取扑草净降解优势菌Pseudomonas FR粗酶液，以藻酸钠作为包埋剂将酶液固定化，比较固定化酶与游离酶对扑草净的作用效果，结果表明，理想条件下，固定化酶的活性相当于游离酶液活性的79％，但温度、pH值等条件的变化对固定化酶的影响很小；对固定化载体进行了优化，确定纤维系为适宜的添加剂，利用固定化酶对受污染土壤进行处理，经六周检测，土壤中扑草净的含量减少85％．     

Preparation of protein-loaded microspheres with size≤10 μm by electrostatic droplet generation technology

AT PRESENT, ALMOST ALL PROTEIN DRUGS HAVE TO BE CLINI- CALLY ADMINISTERED VIA INJECTION ROUTES SUCH AS INTRAVE- NOUS INJECTION. ONE OF THE IMPORTANT PROBLEMS CON- FRONTED IS THAT THESE DRUGS SHOULD BE INJECTED REPEATEDLY DUE TO SHORT HALF-LIFE IN BLOOD. I…     

Green preparation of copper nanoparticle-loaded chitosan/alginate bio-composite: Investigation of its cytotoxicity,antioxidant and anti-human breast cancer properties

In this study, an eco-friendly and low-cost procedure for the in situ fabrication of Cu nanoparticles by using chitosan/alginate hydrogel. The prepared Cu NPs@CS/Alg nanocomposite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. It has been established that chitosan/alginate-capped gold nanoparticles have a spherical shape with a mean diameter from 10 to 20 nm. In the cellular and molecular part of the recent study, the treated cells with Cu NPs@CS/Alg nanocomposite were assessed by MTT assay for 48 h about the cytotoxicity and anti-human breast cancer properties on normal (HUVEC) and breast cancer cell lines i.e. infiltrating lobular carcinoma of breast (UACC-3133), inflammatory carcinoma of the breast (UACC-732), and metastatic carcinoma (MDA-MB-453). In the antioxidant test, the IC50 of Cu NPs@CS/Alg nanocomposite and BHT against DPPH free radicals were 344 and 193 µg/mL, respectively. The IC50 of Cu NPs@CS/Alg nanocomposite were 297, 386, and 359 µg/mL against KYSE-270, OE33, and ESO26 cell lines, respectively. The viability of malignant breast cell line reduced dose-dependently in the presence of Cu NPs@CS/Alg nanocomposite.     

聚乙烯醇-海藻酸钠共固定化葡萄糖氧化酶和过氧化氢酶

酶的固定化是提高酶的稳定及降低使用成本的重要途径．通过制备聚乙烯醇(PVA)-海藻酸钠(SA)复合载体,对共固定化葡萄糖氧化酶(GOD)和过氧化氢酶(CAT)的条件进行了研究,优化了固定化酶制备工艺,研究了固定化酶性质．得出制备固定化酶最佳条件为：载体比例 PVA∶SA＝9．0∶1．5,加酶量10 mg/mL,酶活之比CAT∶GOD＝10∶1．固定化酶的最适反应温度为45℃,比游离酶提高了5℃,最适反应pH 没有发生变化,连续使用6次酶活保留60％．研究结果有一定的应用潜力．