联合收割机割刀驱动行星轮系多目标优化设计

针对联合收割机割刀机构的工作特点,采用2K-H型行星齿轮机构,分析了割刀机构工作原理。通过建立2K-H型行星轮系的优化设计模型,应用NSGA-2算法对2K-H型行星齿轮机构进行多目标优化设计。以最小体积和最大承载力为优化设计目标,通过编制MATLAB程序得到Pareto前沿,进而得到最优解,与以往多目标优化设计比较,设计得到了很好的改善。     

浅析自然保护区管理现状及可持续发展建议

自然保护区是我国可持续发展的重要事业,目前其管理水平还远远不能适应社会发展的需要.笔者通过对自然保护区的现状分析,提出了有利于保护区科学发展的建议.     

花生组培苗嫁接技术的研究

为解决花生组培再生苗及转基因苗驯化移栽成活率低的难题,本试验以花生实生苗作为砧木,对花生嫁接技术进行了研究。试验结果表明:超净台内无菌嫁接效果较好,以再生苗或实生苗为接穗进行无菌嫁接,其成活率均达90%以上,明显高于室内嫁接成活率(71%～72%);无菌嫁接时12～15d苗龄的砧木效果最好;将无菌嫁接苗在培养基中培养3～5d后进行驯化移栽为最佳时期;不同花生基因型嫁接苗成活率在87%～95%;嫁接苗移栽田间后,其成活率高达94%,且100%结果。     

当代大学生共产主义信念的群体差异调查——以广东省六所高校调查情况为例

青年大学生能否树立正确的理想信念不仅关系到个人的成长成才，而且关系到国家和民族的发展方向。基于对广东省六所高校大学生的调查显示，党员大学生、入党积极分子大学生和普通大学生三类不同群体在如何看待坚持马克思主义意识形态的主导地位等几个重大问题上存在不同程度差异。针对此现象，提出以加强社会主义核心价值观教育为突破口，坚定大学生共产主义信念。     

葡萄砧木在贺兰山东麓扦插生根与成苗特性初探

为了加快优良葡萄砧木在贺兰山东麓地区的研究和应用进程,2008～2009年对11个砧木品种进行了硬枝扦插试验,采用目前生产上常用的硬枝扦插技术,研究了在宁夏贺兰山东麓生态条件下,葡萄砧木生根成苗特性的关系,以期为葡萄砧木的选择和大量繁育提供依据,为优良葡萄砧木的大量应用打下一定的基础。     

一株高雄山虫草的分子鉴定

[目的]利用生物信息学方法初步探讨虫草属日本拟青霉的分类地位。[方法]提取日本拟青霉的基因组,并利用通用引物ITSL和ITS4采用PCR技术扩增rDNA18S-28S ITS序列。采用Clustalx1.83和MEGA5软件构建系统发育树,生物信息学比较分析确定其分类地位。[结果]PCR扩增产物为603 bp。将日本拟青霉重新命名为雪花高雄山虫草(Cordyceps takaomontana strain JLsnow)。将虫草重新分类,并对该类群及其特征进行了描述。[结论]从分子水平上说明日本拟青霉与其他虫草之间的差异,该研究为虫草属真菌的分类提供新思路。     

聚乙烯醇共混改性膜作为农药种衣剂成膜剂的性能研究

以水溶性聚合物聚乙烯醇(PVA)和水不溶性聚合物乙酸乙烯-乙烯共聚物(VAE)乳液为原料,采用溶液共混法制备了PVA-VAE共混膜,为农药成膜剂的制备开辟了新途径。红外光谱、透射电镜、激光粒度仪测试结果显示,PVA溶液中的胶束被打开,体系的比表面积急剧增大,两相间的界面消失,说明共混体系分子间具有良好的相容性;透水性与耐水性测定结果表明,PVA-VAE的质量比为80∶ 20、70∶ 30、60∶ 40时其共混膜的性能适用于农药种衣剂的成膜剂;种子发芽试验显示,与单独使用PVA膜相比,引入适当比例VAE后的共混膜用于种子包衣,其耐水性显著提高,渗水率适宜,对种子发芽无明显影响。     

High density lipoprotein subclasses and activities of protein kinase C

AIM: To investigate the relationship between high density lipoprotein (HDL) subclasses and the binding activities of hepatic cell and extra-hepatic cell HDL receptor and intracellular protein kinase C (PKC). METHODS: Using purified pre-β1 HDL and apoE-deficent HDL3 to react with human smooth muscle cells (SMC) and HepG2 cells, then the activities of pre-β1HDL and apoE-deficent HDL3 binding to SMC and HepG2 cells, and the effects of this two HDL subclasses on PKC activities in SMC and HepG2 cells were observed . RESULTS: The results showed that the value of Kd of pre-β1HDL binding to SMC HDL receptor was not only significantly lower than that of apoE-deficient HDL3 (P<0.05), but significantly lower than pre-β1 HDL binding to HepG2 HDL receptor (P<0.05). Cell PKC system was all activated by binding of the two HDL subclasses with SMC HDL receptor, and the effect of pre-β1HDL appeared to be stronger than apoE-deficent HDL3. No change in HepG2 cell PKC activity by binding the two HDL subclasses with HepG2 HDL receptor was observed. CONCLUSIONS: The results indicate that the ability of pre-β1HDL to promote efflux of cholesterol from extra-hepatic cells is stronger than that of apoE-deficent HDL3, and it seems that plasma pre-β1 HDL mainly interacts with extra-hepatic cell HDL receptor, subsequently, activates PKC signal transduction system and promotes the intracellular cholesterol efflux from cells.     

Study on animal intracorneal implantation model with xenogeneic swine corneal stroma

AIM: To study the immunogenicity and biocompatibility of xenogeneic swine corneal stroma as biological carrier for cornea reconstruction and to reconstruct corneal endothelial tissue with this carrier in vitro. METHODS: (1) The lymphocytes from the peripheral blood of F344 rats were immunologically labeled by anti-rat CD25-FITC and anti-rat CD4/CD8-PE, then determined by flow cytometry (FCM) at 12th， 90th day after intracorneal implantation with fresh and dehydrated swine corneal stroma. (2) The fresh and dehydrated grafts made of swine corneal stroma were implanted intralamellarly in corneas of New Zealand rabbits. Clinical examinations were performed monthly and histological examinations were made at 14th， 30th， 60th， 120th and 240th day. (3) The cat corneal endothelial cells were seeded on the Descemet's membrane of the dehydrated swine corneal stroma, then cultured in the medium with epidermal growth factor and laminin for 7 days. The morphology of reconstructed tissue was tested by microscope. RESULTS: (1) Compared to isograft group and negative control, the expression CD4＋CD25＋， CD8＋CD25＋ and CD4＋/CD8＋ of xenograft rat group implantation with swine corneal stroma did not appear significantly different in statistics (P>0.05). (2) In the total 12 rabbits, all the cornea grafts survived without rejection reaction， corneal haze or corneal neovascularization. The fresh grafts got transparent after 2 months, and the dehydrated grafts got transparent after 6 months. Histological study demonstrated both fresh and dehydrated stroma grafts had fused with rabbits'corneal stroma very well without lymphocytes infiltrating. (3) As shown in histological observations, the reconstructed cat corneal endothelial tissue was similar to the nature tissue. Cultured cat endothelial cells connected tightly to each other and attached to the Descemet's membrane closely. CONCLUSION: Swine corneal stroma has low immunogenicity and satisfying biocompatibility,it is an ideal biological carrier for cornea reconstruction in vitro.     

The relationship between high density lipoprotein subclasses and apoE gene polymorphism in obese subjects

AIM: The purpose of this study is to elucidate the relationship between apolipoprotein (apo) E polymorphism and plasma lipid profiles and HDL subclasses in obesity. METHODS: apoE genotype was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 93 obese subjects and 96 nonobese subjects were determined by two-dimensional gel electrophoresis conjunction with immunodetection method. RESULTS: apoE3/3 genotypes and allele ε3 frequency in obese group and the control group were both the highest, but no significant difference. In obese group, the genotype of apoE2 had higher serum apoE/aopCⅢ, HDL2a and lower apoB100, apoCⅢ, HDL3c levels compared with the genotype of apoE3 (P<0.05). In control group, the genotype of apoE2 had higher serum TC and apoE levels, but lower HDL3b level compared with the genotype of apoE3 (P<0.05). CONCLUSION: Polymorphism of the ApoE gene is associated with the distribution of HDL particles in obesity. Allele of ε2 carrier may slow the tendency of HDL particals shifted towards smaller sizes.