SO_2两转两吸流程中“ⅢⅠ-ⅣⅡ”和“ⅢⅡ-ⅣⅠ”换热情况浅析

通过工艺计算，定量分析比较 Ｓ Ｏ２ 转化中“ⅢⅠ－ ⅣⅡ”和“ⅢⅡ－ ⅣⅠ”两种换热流程的差异，论证了就换热情况而言，“ⅢⅠ－ ⅣⅡ”流程优于“ⅢⅡ－ ⅣⅠ”流程     

用柱层析和TLC分离小麦PGIP和植保素

植物抗病能力大小的测定需要比较准确可靠且相对简便的办法。采用接种病菌于植物上观察染菌情况虽然直观，但受病菌本身的生理状态及外界环境影响很大，且不便于定量的表述。因此，选择合适的生理生化指标作为植物抗性大小的衡量标准，对于植物病理的研究具有重要的意义。选择了小麦体系的两种抗性物质－ 小麦植保素和 Ｐ Ｇ Ｉ Ｐ作为小麦的抗性指标来分离分析     

Structure of Cdc42 in complex with the GTPase-binding domain of the 'Wiskott-Aldrich syndrome' protein.

The Rho-family GTP-hydrolysing proteins (GTPases), Cdc42, Rac and Rho, act as molecular switches in signalling pathways that regulate cytoskeletal architecture, gene expression and progression of the cell cycle. Cdc42 and Rac transmit many signals through GTP-dependent binding to effector proteins containing a Cdc42/Rac-interactive-binding (CRIB) motif. One such effector, the Wiskott-Aldrich syndrome protein (WASP), is postulated to link activation of Cdc42 directly to the rearrangement of actin. Human mutations in WASP cause severe defects in haematopoletic cell function, leading to clinical symptoms of thrombocytopenia, immunodeficiency and eczema. Here we report the solution structure of a complex between activated Cdc42 and a minimal GTPase-binding domain (GBD) from WASP. An extended amino-terminal GBD peptide that includes the CRIB motif contacts the switch I, beta2 and alpha5 regions of Cdc42. A carboxy-terminal beta-hairpin and alpha-helix pack against switch II. The Phe-X-His-X2-His portion of the CRIB motif and the alpha-helix appear to mediate sensitivity to the nucleotide switch through contacts to residues 36-40 of Cdc42. Discrimination between the Rho-family members is likely to be governed by GBD contacts to the switch I and alpha5 regions of the GTPases. Structural and biochemical data suggest that GBD-sequence divergence outside the CRIB motif may reflect additional regulatory interactions with functional domains that are specific to individual effectors.     

The implications of viral reservoirs on the elite control of HIV-1 infection

The mechanisms by which a small percentage of HIV-1 infected individuals known as elite suppressors or controllers are able to control viral replication are not fully understood. Early cases of viremic control were attributed to infection with defective virus, but subsequent work has demonstrated that infection with a defective virus is not the exclusive cause of control. Replication-competent virus has been isolated from patients who control viral replication, and studies have demonstrated that evolution occurs in plasma virus but not in virus isolates from the latent reservoir. Additionally, transmission pair studies have demonstrated that patients infected with similar viruses can have dramatically different outcomes of infection. An increased understanding of the viral factors associated with control is important to understand the interplay between viral replication and host control, and has implications for the design of an effective therapeutic vaccine that can lead to a functional cure of HIV-1 infection.     

Sex ratios of the white-tailed antelope ground squirrel (Ammospermophilus leucurus), Indian Wells Valley, San Bernardino County, California

We studied the white-tailed antelope ground squirrel during spring and summer 2006 to determine young-of-the-year and adult sex ratios in the Indian Wells Valley, San Bernardino County, California. We calculated a young-of-the-year sex ratio of 1.45:1 (female to male), whereas the adult sex ratio was approximately 1:1. Our young-ofthe-year sex ratio was greater than the 1.1:1 (female to male) natal sex ratio previously reported. Differences between young-of-the-year and adult sex ratios may represent low female young-of-the-year survivorship in the Indian Wells Valley.     

Enhanced expression of Epstein-Barr virus early antigens by antitubulin agents in a latently infected human lymphoblastoid cell line

28 anticancer agents have been surveyed for Epstein-Barr virus (EBV) activating potency. Two vinca alkaloids with antitubulin activity, vinblastine (VLB) and vincristine (VCR), enhanced the expression of EBV early antigens (EA) in a latently infected human lymphoblastoid cell line (Raji), when used in combination with n-butyrate. Other antitubulin agents, colchicine, colcemid, and podophyllotoxin, had the same effect, although their effects were less than that of the potent tumor promoter, 12-O-tetradecanoyl phorbol-13-acetate (TPA).     

Hybrid antibodies can target sites for attack by T cells

It would be advantageous in the case of certain diseases to be able to focus a strong T-cell response at a chosen target, for example, in treating cancer or infections that have escaped the normal host response. At present, it seems inconceivable that we could use antigen-specific lines or clones of effector T cells for this purpose because of complications due to the major histocompatibility restriction of T-cell specificity and the problem of rejection of transplanted effector cells. Here we describe a novel technology which combines the power of T lymphocytes in eliminating unwanted cells and causing beneficial inflammatory reactions with the great advantages of monoclonal antibodies (their specificity and availability). We show that heteroconjugates of monoclonal antibodies (referred to hereafter as hybrid antibodies), in which one of the component binding sites is anti-T-cell receptor and the other component binding site is directed against any chosen target antigen, can focus T cells to act at the targeted site. Monoclonal antibodies directed against the T-cell receptor, such as the anti-allotype used here, are mitogenic for resting T cells and can be used to induce effector T cells carrying the T-cell receptor determinant which can then be directed against the target by a hybrid antibody.     

Simulation Modeling by Fuzzy Nets

Fuzzy technology is a newly developed discipline based on fuzzy mathematics. In the recent years, it has been successfully applied into many areas, such as process control, diagnosis,evaluation, decision making and scheduling, especially in simulation where accurate mathematical models can not or very hard be established. In this paper, to meet the demands of fuzzy simulation, two fuzzy nets will first be presented, which are quite suitable for modeling the parallel or concurrent systems with fuzzy behavior. Then, a concept of active simulation will be introduced, in which the simulation model not only can show its fuzzy behavior, but also has a certain ability which can actively perform many very useful actions, such as automatic warning, realtime monitoring, simulation re-sult checking, simulation model self-adapting, error recovery, simulating path tracing, system states inspecting and exception handling, by a unified approach while some specified events occur. The simulation model described by this     

Effects of acetaldehyde and/or ethanol on neutral amino acid transport systems in microvillous brush border membrane vesicles prepared from human placenta

Summary At 20 mM of acetaldehyde, the activities of three transport systems of L-alanine distinguished by the difference in their cation dependence, namely 1) Na⁺-specific, 2) Li⁺-dependent, and 3) Na⁺-independent systems, were significantly reduced in a similar manner. Only the Li⁺-dependent system was selectively inhibited at toxic concentrations of acetaldehyde and ethanol.