(2+1)维bidirectional Sawada-Kotera方程的共振多波解和complexiton解

利用线性叠加原则研究了（2+1）维bidirectional Sawada-Kotera （bSK）方程的双线性形式，分别构造了（2+1）维bidirectional Sawada-Kotera方程的共振多波解和complexiton解.特别地，得到了方程的正complexiton解.此外，利用图像展示了解的一些动力学特征.     

Fungitoxicity of m-fluorophenylalanine-containing peptides towards Pythium ultimum

The tripeptide L-m-fluorophenylalanyl-L-alanyl-L-alanine was much more fungitoxic towards Pythium ultimum than the dipeptide L-m-fluorophenylalanyl-L-alanine or m-fluorophenylalanine. The fungitoxicity of the tripeptide was reduced by L-alanyl peptides and phenylalanine, but not by other amino acids. In contrast, the fungitoxicity of m-fluorophenylalanine was unaffected by peptides, and was antagonized by several amino acids. These results suggest the effective delivery of m-fluorophenylalanine into the cell by a tripeptide carrier.     

Objective analysis of the topological organization of the primate cortical visual system.

The primate cortical visual system is composed of many structurally and functionally distinct areas, each receiving and sending about 10 projections from and to other cortical areas. The visual cortex is thus served by many cortico-cortical connections to form a network of considerable complexity. Thus the gross organization of this cortical processing system presents a formidable topological problem: although the spatial position of the areas in the brain is reasonably well established, the gross 'processing architecture' defined by the connections, is less well understood. Here I report an optimization approach that gives both qualitative and quantitative insight into the connectional topology of the primate cortical visual system. This approach supports suggestions that the system is divided into a dorsal 'stream' and a ventral 'stream' with limited cross-talk, that these two streams reconverge in the region of the principal sulcus (area 46) and in the superior temporal polysensory areas, that the system is hierarchically organized, and that the majority of the connections are from 'nearest-neighbour' and 'next-door-but-one' areas.     

Molecular and genetic damage in humans from environmental pollution in Poland.

Extreme environmental pollution such as that found in the highly industrialized Silesian region of Poland has been associated with increased risk of cancer and adverse reproductive outcomes. Among the most prevalent carcinogenic and mutagenic air pollutants in Silesia are the polycyclic aromatic hydrocarbons (PAH) which are largely produced by industrial and residential combustion of coal. Molecular epidemiology aims to prevent disease by using biological markers to identify risks well before clinical onset to allow effective intervention. Here, we use a battery of biological markers to measure molecular and genetic damage in peripheral blood samples from residents of Silesia and from persons living in a rural, less polluted area of Poland. The results show that their exposure to environmental pollution is associated with significant increases in carcinogen-DNA adducts (PAH-DNA and aromatic adducts), in sister chromatid exchange including high-frequency cells, and in chromosomal aberrations as well as a doubling in the frequency of ras oncogene overexpression. We found that aromatic adducts on DNA were significantly correlated with chromosomal mutation, providing us with a molecular link between environmental exposure and a genetic alteration relevant to cancer and reproductive risk.     

具有年龄结构的种群扩散系统反问题的数值解

研究了一类具有年龄结构的种群扩散系统反问题的数值解.对原系统变形后建立了具有高精度的四阶Pade差分格式来计算种群的密度和扩散系数,该格式的截断误差为O(τ2+h4)并且无条件稳定,所得结果能更准确的描述种群密度和扩散系数.数值算例验证了方法的精确性和可靠性.     

铬鞣废液直接循环利用技术的研究与应用

采用淀粉改性水处理剂,并借助气浮法能有效除去铬鞣废液中可溶性油脂、蛋白质及其他杂质,从而消除了铬鞣废液直接循环利用中杂质累计对皮革质量的影响.研究表明,处理后的铬鞣废液利用率可达到90%,且循环利用多次,成品革的性能稳定,从而可实现铬鞣废液的清洁化生产.     

Increased affiliative response to vasopressin in mice expressing the V1a receptor from a monogamous vole.

Arginine vasopressin influences male reproductive and social behaviours in several vertebrate taxa through its actions at the V1a receptor in the brain. The neuroanatomical distribution of vasopressin V1a receptors varies greatly between species with different forms of social organization. Here we show that centrally administered arginine vasopressin increases affiliative behaviour in the highly social, monogamous prairie vole, but not in the relatively asocial, promiscuous montane vole. Molecular analyses indicate that gene duplication and/or changes in promoter structure of the prairie vole receptor gene may contribute to the species differences in vasopressin-receptor expression. We further show that mice that are transgenic for the prairie vole receptor gene have a neuroanatomical pattern of receptor binding that is similar to that of the prairie vole, and exhibit increased affiliative behaviour after injection with arginine vasopressin. These data indicate that the pattern of V1a-receptor gene expression in the brain may be functionally associated with species-typical social behaviours in male vertebrates.     

Human embryonic stem cell lines derived from single blastomeres

The derivation of human embryonic stem (hES) cells currently requires the destruction of ex utero embryos. A previous study in mice indicates that it might be possible to generate embryonic stem (ES) cells using a single-cell biopsy similar to that used in preimplantation genetic diagnosis (PGD), which does not interfere with the embryo's developmental potential. By growing the single blastomere overnight, the resulting cells could be used for both genetic testing and stem cell derivation without affecting the clinical outcome of the procedure. Here we report a series of ten separate experiments demonstrating that hES cells can be derived from single blastomeres. In this proof-of-principle study, multiple biopsies were taken from each embryo using micromanipulation techniques and none of the biopsied embryos were allowed to develop in culture. Nineteen ES-cell-like outgrowths and two stable hES cell lines were obtained. The latter hES cell lines maintained undifferentiated proliferation for more than eight months, and showed normal karyotype and expression of markers of pluripotency, including Oct-4, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81, nanog and alkaline phosphatase. These cells retained the potential to form derivatives of all three embryonic germ layers both in vitro and in teratomas. The ability to create new stem cell lines and therapies without destroying embryos would address the ethical concerns of many, and allow the generation of matched tissue for children and siblings born from transferred PGD embryos.