利用杀菌剂防治松萎蔫病

松萎蔫病是一种非常复杂的病害。据报道,松材线虫(Bursaphelenchus xylophilus)及其携带的细菌诱导了该病,但是对于细菌的的作用尚存争议。笔者筛选出杀细菌剂进行了温室和林间防治松萎蔫病的实验。利用每株3年生赤松(Pinus densiflora)注射3 mg的恶喹酸,松萎蔫病防效达到71 %。利用恶喹酸或阿维菌素及两者混合物对大约20年生赤松的试验表明,3种处理均显示了很高的防效。以上结果证明伴生细菌是诱导松萎蔫病的必要因素,对松萎蔫病可利用杀细菌剂或杀细菌剂与杀线剂混合物进行防控。     

尾部喷射对流向振荡柱体尾流旋涡脱落的抑制

强迫振荡柱体绕流旋涡脱落的抑制具有重要工程意义,但比静止柱体尾流的抑制更加困难,乍前这方面的研究很少．本文采用尾部喷射方法对流向振荡圆柱尾流旋涡脱落进行抑制实验,雷诺娄Re=V∞D／慌围为2700-9800,柱体振荡幅值A／D=O．2,柱体振荡频率范围feD／V∞=0-0．36,其中亿为来沥速度,D为柱体直径．沿圆柱母线开一个与圆柱等长、宽度为h／D=O．015的缝隙,用于喷射空气．喷射麦度比W％范围为0-18,相应的流量比hVb／DV∞范围为0-0．27．风洞中的烟线显示和热线测量结果表明当喷射速度比Vb／比（或hVblDV∞）介于其下临界值和上临界值之间时,振荡柱体两侧的尾流旋涡脱落被辛效抑制．发现在非锁频和锁频两种状态下均能抑制旋涡脱落．在振频fe／V∞和喷射速度比W亿（曼hVb／DV∞）组成的平面坐标系内找出了有效抑制旋涡脱落的区域,研究了有效区域随雷诺数的变化和喷身角对抑制效果的影响,并探讨了旋涡脱落抑制机理．     

Critical role of TRAF3 in the Toll-like receptor-dependent and -independent antiviral response

Type I interferon (IFN) production is a critical component of the innate defence against viral infections. Viral products induce strong type I IFN responses through the activation of Toll-like receptors (TLRs) and intracellular cytoplasmic receptors such as protein kinase R (PKR). Here we demonstrate that cells lacking TRAF3, a member of the TNF receptor-associated factor family, are defective in type I IFN responses activated by several different TLRs. Furthermore, we show that TRAF3 associates with the TLR adaptors TRIF and IRAK1, as well as downstream IRF3/7 kinases TBK1 and IKK-epsilon, suggesting that TRAF3 serves as a critical link between TLR adaptors and downstream regulatory kinases important for IRF activation. In addition to TLR stimulation, we also show that TRAF3-deficient fibroblasts are defective in their type I IFN response to direct infection with vesicular stomatitis virus, indicating that TRAF3 is also an important component of TLR-independent viral recognition pathways. Our data demonstrate that TRAF3 is a major regulator of type I IFN production and the innate antiviral response.     

Specific in vitro antibody response to influenza virus by human blood lymphocytes.

Advances in understanding of human immune responses depend, for obvious reasons, on the use of in vitro techniques for culture of peripheral blood lymphocytes (PBL). We report here that specific antibody responses to influenza virus can readily be obtained using simple, reproducible methods. The system will be useful for the analysis of the cellular requirements for antibody production, the genetics of immune responsiveness and in clinical studies of immunosuppressed and immunodeficient patients.     

窄条控制件对流向振荡柱体尾流旋涡脱落的抑制

在流向振荡圆柱体尾流中施加一个静止的窄条控制件,对尾流涡脱落及作用于柱体的平均和脉动力进行抑制.未加控制情况下,存在非锁频和3种锁频状态的涡脱落模式.流动显示及尾流脉动速度谱和脉动升力谱的分析表明,当控制件位于有效控制区域时,可抑制非锁频和2种锁频状态下的旋涡脱落,并且使脉动升力和平均阻力有明显减少.本文研究了柱体的振频、雷诺数,窄条宽度及阻塞度对有效区的影响并探讨了控制机理.     

A diverse range of gene products are effectors of the type I interferon antiviral response

The type I interferon response protects cells against invading viral pathogens. The cellular factors that mediate this defence are the products of interferon-stimulated genes (ISGs). Although hundreds of ISGs have been identified since their discovery more than 25 years ago, only a few have been characterized with respect to antiviral activity. For most ISG products, little is known about their antiviral potential, their target specificity and their mechanisms of action. Using an overexpression screening approach, here we show that different viruses are targeted by unique sets of ISGs. We find that each viral species is susceptible to multiple antiviral genes, which together encompass a range of inhibitory activities. To conduct the screen, more than 380 human ISGs were tested for their ability to inhibit the replication of several important human and animal viruses, including hepatitis C virus, yellow fever virus, West Nile virus, chikungunya virus, Venezuelan equine encephalitis virus and human immunodeficiency virus type-1. Broadly acting effectors included IRF1, C6orf150 (also known as MB21D1), HPSE, RIG-I (also known as DDX58), MDA5 (also known as IFIH1) and IFITM3, whereas more targeted antiviral specificity was observed with DDX60, IFI44L, IFI6, IFITM2, MAP3K14, MOV10, NAMPT (also known as PBEF1), OASL, RTP4, TREX1 and UNC84B (also known as SUN2). Combined expression of pairs of ISGs showed additive antiviral effects similar to those of moderate type I interferon doses. Mechanistic studies uncovered a common theme of translational inhibition for numerous effectors. Several ISGs, including ADAR, FAM46C, LY6E and MCOLN2, enhanced the replication of certain viruses, highlighting another layer of complexity in the highly pleiotropic type I interferon system.     

Interferon modulation of cellular microRNAs as an antiviral mechanism

RNA interference through non-coding microRNAs (miRNAs) represents a vital component of the innate antiviral immune response in plants and invertebrate animals; however, a role for cellular miRNAs in the defence against viral infection in mammalian organisms has thus far remained elusive. Here we show that interferon beta (IFNbeta) rapidly modulates the expression of numerous cellular miRNAs, and that eight of these IFNbeta-induced miRNAs have sequence-predicted targets within the hepatitis C virus (HCV) genomic RNA. The introduction of synthetic miRNA-mimics corresponding to these IFNbeta-induced miRNAs reproduces the antiviral effects of IFNbeta on HCV replication and infection, whereas neutralization of these antiviral miRNAs with anti-miRNAs reduces the antiviral effects of IFNbeta against HCV. In addition, we demonstrate that IFNbeta treatment leads to a significant reduction in the expression of the liver-specific miR-122, an miRNA that has been previously shown to be essential for HCV replication. Therefore, our findings strongly support the notion that mammalian organisms too, through the interferon system, use cellular miRNAs to combat viral infections.     

纳米铝佐剂诱导鸡提前产生抗AIVH9体液免疫应答

接种灭活油佐剂疫苗是目前国内防控禽流感主要的措施,为有效防控禽流感的流行发挥了重要的作用,但灭活苗首次接种后需要较长时间抗体才能达到有效保护水平.纳米颗粒具有独特的生物学特性,作为疫苗佐剂能引起机体强烈的免疫应答.本研究用纳米铝颗粒作为AIV H9的佐剂,结果显示,小鸡产生有效免疫保护抗体时间较常规油佐剂疫苗提前4天且无副反应,但抗体峰值和持续时间均低于油佐剂疫苗.氢氧化铝纳米颗粒作为佐剂可能对禽流感等重大传染病的紧急预防接种具有潜在的应用价值.     

Murine cells expressing an HLA molecule are specifically lysed by HLA-restricted antiviral human T cells

Class I HLA (histocompatibility locus antigen) molecules are the targets of allospecific cytolytic T lymphocytes (CTL) in graft rejection, and constitute the restricting elements necessary for the interaction between antiviral CTL and virus-infected cells. Cells expressing only one HLA in the absence of other human molecules would provide a remarkable model for studying the function of these molecules. However, HLA+ murine cells transfected with human genes are generally not lysed by allospecific human CTL, and this is ascribed to insufficient HLA expression, lack of human beta 2-microglobulin, alteration of HLA molecules or absence of receptors for human T8 or LFA1 molecules in murine cells. Here we report, for the first time, the specific lysis of virus-infected HLA+ murine cells by HLA-restricted antiviral human CTL. Therefore, these murine cells constitute an excellent model for studying the role of HLA molecules.     

筒形消焰器的灭焰机理

本文以12.7mm机枪进行实验的结果为依据从理论上分析了筒形消焰器对火药气体流动的影响,揭示了筒形消焰器的灭焰机理。