汉代单耳三足罐研究

我国西北地区的一部分汉墓中随葬单耳三足罐,是一种实用器。本研究表明,汉代西北地区单耳三足罐的出现可能与汉代匈奴等游牧民族的内迁有关,是游牧民族和中原人群文化互动的结果。这种文化现象在东汉中期以后随着使用者迁移到关中地区并完全融入中原文化而消失。

中国古代民族融合及其文学意义的思考

就中国古代民族融合与文学的关联互动而言,所谓民族融合一般指作为社会文化共同体的民族之间的融合。民族融合始终是中国古代文学发展的重要背景之一,在很大程度上影响着整个中国古代文学史的总体走向。民族融合的文学意义主要体现在体质融合和文化融合两大方面。这也是其文学功效实现的两大路径。体质融合与文化融合往往扭织在一起,或互为因果,或形成一种合力而共同对文学产生影响。两者对中国古代文学影响的时效也不同,前者呈渐现性,后者呈即时性。

Production of Somatic Hybrid Plants Between Two Types of Wheat Protoplasts and the Protoplasts of Haynaldia villosa

小麦 (TriticumaestivumL .)济南 177的两种原生质体 ,一种来自快速生长的悬浮细胞 ,它们因长期继代而丧失分化能力 ,其染色体只有 2n =2 4～ 2 8;另一种来自可以再生的愈伤组织 ,其原生质体不能持续分裂。它们中任一种与UV照射过的簇毛麦原生质体融合均不能再生植株。然而当它们混合在一起作为受体时 ,能够获得再生绿色植株。细胞核基因和胞质基因的分析证明这些绿色植株是杂种。以上事实说明这两种原生质体在融合时存在某些互补的关系 ,讨论了这种融合方式的可能作用及重要性。

Fluorescent vital staining of plant sexual cell nuclei with DNA-specific fluorochromes and its application in gametoplast fusion

DNA-binding fluorochromes are often used for vital staining of plant cell nuclei. However, it is not always sure whether the cells after staining still remain in living state. We chose several criteria to estimate the validity of real vital staining for sexual cell nuclei. These were: the cytoplasmic streaming in pollen tubes whose nuclei were stained, the simultaneous visualization of fluo-rochromatic reaction and nucleus staining in isolated generative cells, and the capability of isolated, prestained generative or sperm cells to fuse with other protoplasts. The results confirmed that 4',6-diamidino-2-phenylindole (DAPI), Hoechst 33258 and mithramycin could be used as real vital stains, though their efficiency varied from case to case; among them DAPI showed best effect. The fluorescent vital staining technique offered a useful means fori-dentification and selection of heterokaryons in gametoplast manipulation studies.

Improvement of chromium biosorption through protoplast electrofusion between Candida tropicalis and Candida lipolytica

Protoplasts from Candida tropicalis and Candida lipolytica were fused under an optimized electrofusion （electrical pulse strength 6 kV/cm, pulse duration time 40μs and pulse times 5） and then regenerated on YEPD media for achieving new genotypes with higher chromium loading capacity. A target fusant RHJ-004 was screened out by its chromium resistance and chromium-sorbing capacity tests for further research. The comparative study of applicability shows that the fusant has better performance than its parent strains in respect of solution pH, biomass concentration and chromium loading capacity. Especially for treating low concentration Cr（VI） （〈20 mg/L）, above 80% chromium is sequestered from the aqueous phase at pH 1-9. Atomic force microscopy （AFM） visualizes the distribution of chromium on the binding sites of the cells, suggesting that the altered surface structure and intracellular constitutes of the fusant associate with its increased biosorption capacity. The rapid biosorption processes of chromium foUow the Langmuir model well.

Effect of Riboflavin Operon Dosage on Riboflavin Productivity in Bacillus Subtilis

After deregulating the purine and riboflavin synthesis in the Gram-positive bacterium Bacillus subtilis,it is critical to amplify riboflavin operon with appropriate dosage in the host strain for remarkable increase of riboflavin production.Bacillus subtilis RH13, a riboflavin-producing strain, was selected as host strain in the construction of engineering strains by protoplast fusion. The integrative plasmid pRB63 and autonomous plasmid pRB49, pRB62 containing riboflavin operon of B.subtilis 24 were constructed and transformed into the host strain respectively. Increasing one operon copy in B.subtilis RH13 results in about 0.4 g/L improvement in riboflavin yield and the appropriate number of operon copies was about 7—8. Amplifying more riboflavin operons is of no use for further improvement of yield of riboflavin. Furthermore, excessive operon dosage results in metabolic unbalance and is fatal to the host cells producing riboflavin.

3D modeling of geological anomalies based on segmentation of multiattribute fusion

3D modeling of geological bodies based on 3D seismic data is used to define the shape and volume of the bodies, which then can be directly applied to reservoir prediction, reserve estimation, and exploration. However, multiattributes are not effectively used in 3D modeling. To solve this problem, we propose a novel method for building of 3D model of geological anomalies based on the segmentation of multiattribute fusion. First, we divide the seismic attributes into edge- and region-based seismic attributes. Then, the segmentation model incorporating the edge- and region-based models is constructed within the levelset- based framework. Finally, the marching cubes algorithm is adopted to extract the zero level set based on the segmentation results and build the 3D model of the geological anomaly. Combining the edge-and region-based attributes to build the segmentation model, we satisfy the independence requirement and avoid the problem of insufficient data of single seismic attribute in capturing the boundaries of geological anomalies. We apply the proposed method to seismic data from the Sichuan Basin in southwestern China and obtain 3D models of caves and channels. Compared with 3D models obtained based on single seismic attributes, the results are better agreement with reality.

The development trend of paper-based media under the media convergence trend

The emergence of media convergence have so huge impact on paper-based media that paper-based media no longer has a monopoly. Some people assert that paper-based media will come to an end. However, the author believes that the paper media will not come to an end under the media convergence trend. It will develop parallel with media integration. The reason why the author has this view is that, on one hand, paper-based media has its unique physical characteristics. In the real world, paper media brought us the aesthetic experience by ＂five senses＂ . It cannot be replaced by the media convergence. The paper media will also make survival steering dimension; on the other hand, cultural heritage of the paper media make itself a unique appreciation of the value and not transcendent. Therefore, the paper media in the media convergence trend will continue to exist and turned to be ＂concept book＂ that admiring is the main part and reading supplemented.

High throughput monoclonal antibody generation by immunizing multiple antigens

Recognizing proteins via the production of highly specific monoclonal antibodies(mAbs)is crucial to identifying proteins for proteomic research.However,traditional mAb generation is time-consuming with low efficiency.In this study,we assessed the high throughput method of producing mAbs by immunizing mice with multiple antigens in order to obtain hybridomas against these multiple antigens in one cell fusion.We selected eight proteins that play important roles in human physiological or pathological processes.These proteins were mixed and simultaneously administered to one mouse.We observed the immunizing period for 10 d,and determined the effect of liquid medium and semi-solid medium in hybridoma generation.As a result,all eight immunogens induced antibodies in the immunized mouse in one cell fusion,we obtained hybridomas specific to all eight proteins by enzyme-linked immuno sorbent assay(ELISA)screening,hybridomas against five out of eight showed specific positive in Western-blotting assays.This indicates that we generated mAbs specific to eight proteins in one cell fusion,greatly increasing the efficiency of mAb generation.Furthermore,we observed that hybridomas selected from the liquid medium and semi-solid medium showed different reactivity to antigens.Our study established high-throughput and time-saving methods for production of mAbs.These results provide alternative approaches for increasing the efficacy of mAb generation.