关于自正交的整表代数码

整表代数是群代数的推广,它的理想是群代数码的推广.本文给出了整表代数的 单边理想是自正交理想的必要充分条件.

Expression of Integrin α4 in Osteosarcoma and Significance

Objective： To investigate the expression of integrin α4 in osteosaxcoma and significance. Methods- Forty-six patients with osteosarcoma （Enneking Ⅰ-Ⅲ） were analyzed for the expression of α4 integrin subunit using immunohistochemical method. Results： Twenty-nine （63.04%） of 46 samples demonstrated positive （＋-＋＋） integrin α4 expression. Loss expression of integrin α4 was observed in the patients with advanced Enneking stage （P=0.0040） and with metastatic disease at presentation （P=0.0158）. Integrin α4 expression correlated with cell differentiation, the level of malignancy and the invasive behavior of osteosaxcoma. Conclusion： The loss expression of integrin α4 subunit might be a predictor indicating the invasive potential of osteosarcoma and play a role in metastasis of osteosaxcoma patients.

Characterization of transgene integration pattern in F4 hGH-transgenic common carp (Cyprinus carpio L.)

The integration pattern and adjacent host sequences of the inserted pMThGH-transgene in the F4 hGH-transgeniccommon carp were extensively studied. Here we show that each F4 transgenic fish contained about 200 copies of thepMThGH-transgene and the transgenes were integrated into the host genome generally with concatemers in a head-to-tail arrangement at 4-5 insertion sites. By using a method of plasmid rescue, four hundred copies of transgenes fromtwo individuals of F4 transgenic fish, A and B, were recovered and clarified into 6 classes. All classes of recoveredtransgenes contained either complete or partial pMThGH sequences. The class I, which comprised 83% and 84.5%respectively of the recovered transgene copies from fish A and B, had maintained the original configuration, indicatingthat most transgenes were faithfully inherited during the four generations of reproduction. The other five classes weredifferent from the original configuration in both molecular weight and restriction map, indicating that a few transgeneshad undergone mutation, rearrangement or deletion during integration and germline transmission. In the five types ofaberrant transgenes, three flanking sequences of the host genome were analyzed. These sequences were common carpβ-actin gene, common carp DNA sequences homologous to mouse phosphoglycerate kinase-1 and human epidermalkeratin 14, respectively.

关于整表代数的同构

对任意整表基为T的整表代数,研究了代数整数环的一个子环R上的整R-代数RT,证明了两个整表代数之间的一个R-代数同构必是一个整表代数同构,只要它与一种标准化变换相容.

Non-integrating lentiviral vectors based on the minimal S/MAR sequence retain transgene expression in dividing cells

Safe and efficient gene transfer systems are the basis of gene therapy applications. Non-integrating lentiviral(NIL) vectors are among the most promising candidates for gene transfer tools, because they exhibit high transfer efficiency in both dividing and non-dividing cells and do not present a risk of insertional mutagenesis. However, non-integrating lentiviral vectors cannot introduce stable exogenous gene expression to dividing cells, thereby limiting their application. Here, we report the design of a non-integrating lentiviral vector that contains the minimal scaffold/matrix attachment region(S/MAR) sequence(SNIL), and this SNIL vector is able to retain episomal transgene expression in dividing cells. Using SNIL vectors, we detected the expression of the eGFP gene for 61 days in SNIL-transduced stable CHO cells, either with selection or not. In the NIL group without the S/MAR sequence, however, the transduced cells died under selection for the transient expression of NIL vectors. Furthermore,Southern blot assays demonstrated that the SNIL vectors were retained extrachromosomally in the CHO cells. In conclusion,the minimal S/MAR sequence retained the non-integrating lentiviral vectors in dividing cells, which indicates that SNIL vectors have the potential for use as a gene transfer tool.

Pairwise interactions in gene expression determine a hierarchical transcriptional profile in the human brain

The orchestrated expression of thousands of genes gives rise to the complexity of the human brain.However,the structures governing these myriad gene-gene interactions remain unclear.By analyzing transcription data from more than 2000 sites in six human brains,we found that pairwise interactions between genes,without considering any higher-order interactions,are sufficient to predict the transcriptional pattern of the genome for individual brain regions and the transcriptional profile of the entire brain consisting of more than 200 areas.These findings suggest a quadratic complexity of transcriptional patterns in the human brain,which is much simpler than expected.In addition,using a pairwise interaction model,we revealed that the strength of gene-gene interactions in the human brain gives rise to the nearly maximal number of transcriptional clusters,which may account for the functional and structural richness of the brain.

Graphene-GaN Schottky diodes

The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse leakage current of 1.0 × 10^-8 A/cm^2 at -5 V were observed. The Schottky barrier heights, as determined by the thermionic emission model Richardson plots, and barrier inhomogeneity model, were 0.90, 0.72, and 1.24 ± 0.13 eV, respectively. Despite the predicted low barrier height of -0.4 eV at the graphene-GaN interface, the formation of excellent rectifying characteristics with much larger barrier heights is attributed to the presence of a large number of surface states （1.2 x 1013 states/cm2/eV） and the internal spontaneous polarization field of GaN, resulted in a significant upward surface band bending or a bare surface barrier height as high as of 2.9 eV. Using the S parameter of 0.48 （measured from the work function dependence of Schottky barrier height） and the mean barrier height of 1.24 eV, the work function of graphene in the Au/graphene/GaN stack could be approximately estimated to be as low as 3.5 eV. The obtained results indicate that graphene is a promising candidate for use as a Schottky rectifier in GaN semiconductors with n-type conductivity.